Monthly Weather Bulletin

Transcription

Monthly
y Weather
Bulletin
No. 231
JULY 2005
Dry in north, but
heavy falls in south
and east;
warm and dull
The weather was dry with light winds for the beginning of the Tall Ships Race on the 9th;
pictured here is Asgard II after setting sail from Waterford (picture: Irish Examiner)
INSIDE
Summary: Rainfall totals for July varied
considerably across the country. Bands
of heavy rain affected parts of Leinster
and Munster during the last week,
while other areas received little. There
were exceptionally heavy falls near
southern and southeastern coasts on
the 23rd/24th, while another band of
heavy rain affected southeastern and
eastern areas on the 28th/29th. Severe
thunderstorms developed over the
southern third of the country during
the evening of the 12th, giving some
torrential falls locally, while a tornado
developed during the same evening
near Myshall, Co. Carlow (see page 2).
This variation in rainfall totals across
the country is reflected in the fact that,
while it was the driest July at Malin
Head since 1983, it was the wettest at
Rosslare since records began there in
1956. The number of wetdays (days
with 1mm or more rainfall) during the
month was close to the normal range
for July of between 9 and 13. July was a
warm month everywhere, with mean
air temperatures of around one degree
above normal generally. The warmest
R ainfall
ainfall .................... 10
Tempera
emperature
ture ............ 12
Sunshine ................. 14
World
........... 15
orld Weather
eather...........
Featur
e .................... 16
eature
Carlow tornado on 12th- page 2
Wind & Elements ......... 4
Marine & Pressur
e ....... 5
Pressure
Agmet /Lab
/Lab ................. 6
Diary .......................... 8
July 1955 was the sunniest
month on record
Produced by Met Éireann,
Glasnevin Hill, Dublin 9.
Annual subscription 80
For more informationtel: +353-1-8064260
fax: +353-1-8064216
[email protected]
www.met.ie/climate
Notes on the tables and map
showing location of stations
appear in January issue
2
WEATHER
July 2005
Tornado in County Carlow on 12th
After hot and sunny weather everywhere on the 10th and 11th,
the morning of the 12th was again fine and dry over the country,
with temperatures rising above 25°C at inland stations. During
the afternoon, however, convective clouds developed over the
southern half of the country, producing heavy showers with
thunderstorms in the southwest and southeast. Falls of between
20 and 25mm within a 3-hour spell were recorded over parts of
Kerry, Cork and Tipperary. Around 1600UTC, a tornado
developed in the Garryhill area of County Carlow, just west of
Mount Leinster. It was observed reaching the ground for a few
seconds, before retreating back into the sky and remaining
visible as a funnel cloud for up to15 minutes. The tornado was
very localised in its extent and no damage was reported.
(pictures courtesy Anthony O’Shea & Liam Clarke)
Radar rainfall chart
at 1645UTC on 12th
0.1
0.6
1.5
3.6
9.0
22
55
mm/hour
spell of weather was in the period 10th
to 13th, when maxima of over 25°C
were recorded at inland stations and
reached around 30°C in places; coastal
areas of the north and northwest were
considerably cooler, however. Daily
maximum values on either the 11th or
12th were the highest for July since 1989
at around half the stations in the
Left
In India's western state of Maharashtra, exceptionally heavy
rainfall was recorded on the 26th when 944mm of rain fell in
the state capital of Mumbai (Bombay). This set a new 24-hour
rainfall record for the country, breaking the old record of
838mm measured at Cherrapunji on July 12th, 1910.
This unprecedented rainfall produced massive and
widespread flooding that was responsible for the deaths of
over 1,000 people in the Maharashtra state, including at least
429 in the city of Mumbai. Estimated economic losses were
put at around 3 billion euro.
(picture courtesy NOAA, US Department of Commerce)
3
WEATHER
July 2005
Visible satellite image
at 1607UTC on 24th
daily values on record for July.
1st to 8th: Low pressure to the northwest
or north of Ireland brought an unsettled
start to the month, with rain or showers in
most places each day. Mild and humid
southwesterly winds at first became
gradually west to northwesterly in direction
during the period; gale gusts were recorded
at coastal stations on the 2nd and 3rd.
Daily sunshine values were generally low,
with the exception of the 4th.
9th to 13th: An Atlantic anticyclone
moved slowly northeastwards over Ireland,
before retreating to the southwest. Mainly
dry and sunny in all areas, but it was
cloudier in the extreme north, while locally
heavy thunderstorms developed over the
south on the 12th. Becoming very warm
with maximum temperatures of over 25°C
in many places between the 10th and 12th.
Widespread fog at times, especially on the
10th.
14th to 27th: Temperatures returned to
near normal values, as weak frontal
systems brought outbreaks of mainly light
rain on several days. A more active system
brought a spell of very heavy rain over
Munster and south Leinster on the
23rd/24th, giving localised flooding. The
period was mainly dull, while light westerly
winds predominated.
28th to 31st: Low pressure close to the
east coast brought a slow-moving band of
heavy rain over eastern areas in a cool
northeasterly airstream, becoming more
extensive while gradually dying out. Dull
throughout.
Synoptic chart at 0600UTC on 24th
Above
July was a dry month in
most areas, but heavy falls
were recorded during the
last week near southern and
eastern coasts. A band of
heavy rain on the 24th over
southern areas gave a fall
of 73mm at Cork Airport.
country. Sunshine totals were below
normal except in the south and it was
particularly dull in the north. Almost
all stations measured their highest
daily sunshine values on the 11th;
values of 15.5 and 15.6 hours
respectively at Casement Aerodrome
and Dublin Airport were their highest
Wind and elements: Mean windspeeds
for the month of between 6 and 10 knots
(11 and 19 km/hour) were below normal
almost everywhere. The highest gust of
the month, 61 knots (113 km/hour), was
measured at Belmullet on the 2nd.
Thunder was recorded on the 3rd, 12th
and 13th, with hail observed at Valentia
Observatory on the 3rd. There was
widespread fog in the periods 9th to 13th
and 20th to 22nd.
4
WIND & ELEMENTS
July 2005
ELEEMEENTS
WIND (KNOTS)
County /
Station
Mean
speed
CO. CLARE
SHANNON AIRPORT
CO. CORK
CORK AIRPORT
CO. DONEGAL
MALIN HEAD
CO. DUBLIN
CASEMENT AERODROME
DUBLIN AIRPORT
CO. KERRY
VALENTIA OBSERVATORY
CO. KILKENNY
KILKENNY
CO. MAYO
BELMULLET
CONNACHT AIRPORT
CO. MONAGHAN
CLONES
CO. OFFALY
BIRR
CO. WESTMEATH
MULLINGAR II
CO. WEXFORD
ROSSLARE
Max. 10-min. mean
dir. speed date/hour
8.4
200° 28
8.6
Max. Gust
dir. speed date/time
2/12
210° 37
Days with
Hours with
gales gale gusts gale gusts
Thunder
Fog
2/1105
0
2
7
0
0
0
0
1
070° 22 24/10
060° 33 24/0626
0
0
0
0
0
0
0
8
8.6
210° 38
3/02
210° 52
3/0114
1
4
23
0
0
0
0
3
7.3
8.8
210° 24
200° 27
2/19
2/18
210° 38
210° 38
2/2057
2/1750
0
0
3
2
6
5
0
0
0
0
0
0
0
0
1
2
6.8
200° 23
2/15
200° 35
2/1421
0
2
3
0
0
1
1
6
5.9
200° 22
2/18
190° 30
2/1704
0
0
0
n/a
0
9.2
7.7
210° 37
200° 24
2/22
2/21
230° 61
210° 37
2/2219
2/1932
1
0
4
2
26
6
0
0
0
0
5.9
190° 21
2/14
210° 33
2/2256
0
0
0
n/a
0
---- n/a ----
5.5
190° 20 2/14
280° 20 18/14
190° 31
2/1225
0
0
0
n/a
0
---- n/a ----
5.2
200° 18
190° 30
2/1324
0
0
0
n/a
0
---- n/a ----
8.2
030° 33 24/16
030° 44 24/1534
0
2
15
0
0
2/15
Valentia Observatory
Calm: 1.6%
Snow Snow Lying Hail
Calm: 0.7%
NE
W
0
6
16
0
0
NE
E
W
SE
S
0
0
N
NW
E
SW
0
0
Dublin Airport
N
NW
---- n/a ----
SW
0 1 2 3 4%
SE
S
FREQUENCY OF WIND DIRECTION
MARINE OBSERVATIONS FROM
IRISH MARINE DATA BUOY NETWORK
Wind Direction
degrees from north
5
MARINE & PRESSURE
July 2005
360
300
Sea
surface
temp.
Mean
wind
speed
Max.
10-min
wind
Mean
wave
height
Max.
wave
height
M1
15.6
11.3
28
1.9
6.0
M2
13.5
11.1
27
0.8
2.7
M3
16.1
13.2
28
1.8
4.8
M4
15.4
12.0
34
1.8
6.8
M5
15.6
12.9
26
1.2
2.9
Buoy
200
(°C)
100
(knots)
(knots)
(m.)
(m.)
0
Wind Speed
40
knots
30
20
10
Malin 15.1 (1.2°C above normal)
Head
0
Sea Temperature
Summary of Mean Monthly Values
19
°C
18
z Malin Head
17
16
M4
15
14
Wave Height
12
metres
10
M2
M1
8
6
4
2
0
1
5
10
15
DATE
20
25
M5
31
Hourly wind and wave conditions at M1 (53°07’N, 11°12’W)
10
MEAN ATMOSPHERIC PRESSURE
M3
16
60˚N
101
6
1024
50˚N
H
1017
H
1026
40˚N
4
Mean sea level pressure values for the month ranged
narrowly, from just under 1016hPa in the northeast
to over 1017hPa in the southwest, close to the
normal values for July. Pressure was highest around
mid-month, when anticyclonic weather dominated;
the highest pressure value, 1035.4hPa, was recorded
at Belmullet on the 11th. This was the highest July
value at the station since 1996. The lowest pressure
of the month, 998.6hPa, was measured at Cork
Airport on the 24th.
L
1015
Monthly mean MSL pressure, based on 1200 UTC values
1040
1030
1020
1010
1000
--•-- Valentia Observatory
—•— Malin Head
990
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
Mean daily Mean Sea Level pressure (hPa)
6
AGMET / LABORATORY
Mean 100mm
Soil Temperatures (°C)
at 0900UTC
Soil Temperatures at 0900UTC
15.5
(+0.9)
(difference from 1961-90 normals
in brackets)
16.7
14.6
17.3
(+2.1)
17.3
(+1.3)
17.9
(+2.1)
17.4
(+1.7)
18.3
(+2.0)
16.9
(+2.0)
17.6
(+0.9)
16.4
(+1.1)
45/65
34/62
31/51
32/62
36/49
69/32
56/32
50/63
63/53
Soil Moisture Deficits (mm)
10th of month / end of month
77/0
34/38
(0 represents field capacity,
-10 saturation)
42/5
°C
County/
Station
17.1
(+2.2)
(+1.5)
July 2005
100mm 200mm 300mm
CO. CLARE
SHANNON AIRPORT
CARRON
CO. CORK
FERMOY (MOORE PARK)
CORK AIRPORT
SHERKIN ISLAND
BALLINCURRIG (PEAFIELD)
CO. DONEGAL
MALIN HEAD
CO. DUBLIN
DUBLIN AIRPORT
CASEMENT AERODROME
CO. KERRY
CO. KILKENNY
KILKENNY
CO. LEITRIM
BALLINAMORE
CO. LIMERICK
MOUNT RUSSELL
CO. LOUTH
ARDEE (BOHARNAMOE)
CO. MAYO
BELMULLET
STRAIDE
CONNACHT AIRPORT
CO. MEATH
WARRENSTOWN
CO. MONAGHAN
CLONES
CO. OFFALY
BIRR
CO. TIPPERARY
FETHARD (PARSONSHILL)
CO. WATERFORD
DUNGARVAN (CARRIGLEA)
CO. WESTMEATH
MULLINGAR II
CO. WEXFORD
JOHNSTOWN CASTLE
ROSSLARE
JOHN F. KENNEDY PARK
CLONROCHE (KNOXTOWN)
Chemical Analysis of Precipitation and Air Samples
at Valentia Observatory
electrical conductivity (μS/cm)
PRECIPITATION
250
8
350
7
200
pH and electrical
conductivity are
not available on dry
days (<0.2mm)
150
100
6
5
50
4
0
3
data shown here are interim values and are subject to change
1.2
SO2-S
0.8

0.6
SO4-S
z z z
(μgs/m3)
0.4
0.2
0
1
17.3
17.7
17.9 17.5
16.4 16.7
17.1
16.5 16.0
17.8
17.0
17.5
16.8
15.5 15.7
15.9
16.9 17.2
17.4 17.5
17.2
17.4
17.9 18.1
18.6
18.3 18.6
18.8
17.0 16.9
16.8
15.6 16.3
17.4 17.3
17.3
16.7 17.6
16.5
14.6 15.1
18.5
17.3 17.9
18.1
17.1 17.4
17.5
17.3 17.8
18.1
16.4
16.3 17.2
17.3
17.7
17.3 17.6
18.3
17.8
17.6
17.9
17.0
17.7
17.8
17.9
17.5
17.6
18.0
17.7
17.2
Acid rain occurs when
pollutants combine with
moisture in the air to form
sulphuric or nitric acid. pH is
the simplest way of
measuring the acidity of
precipitation. Usually pH of
7.00 is considered neutral
but this is not the case in
rainfall samples. Pure water
in the atmosphere has an
equilibrium pH value of 5.65
at 20°C owing to carbon
dioxide in the air dissolving
to form carbonic acid. Any
value below pH 5.65 is
considered acid while any
value above is considered
alkaline.
Sulphur dioxide and
sulphate in air contribute to
the formation of sulphuric
acid; nitrate in air contributes
to the formation of nitric
acid.
AIR
1
pH
16.9 16.9
17.4
3
5
7
9
11
13
15
17
19
21
23
25
27
29
31
Conductivity measures the
total ion activity in the
rainfall, i.e. the higher the
conductivity the greater the
number of ions present.
7
AGMET
TEMPERATURE
mean wind speed (m/s) 2m a.g.l.
P.E. (Penman) (mm)
-
41.7 64.7 27.2 133.6
-
-
0
0
0
0
107
128
114
348
53 -1.1 4 1 16.3
72 4.6 13 0 18.2
53 2.4 22 0 16.5
177 -1.1 4 1 17.0
16.1
17.8
16.6
16.8
38.6
63.5
17.7
119.8
93
4
19
28
4
0
0
0
0
118
139
121
378
62
83
59
205
6.9
7.7
6.7
6.7
3
19
28
28
0
0
0
0
16.8
18.9
16.7
17.4
16.4
18.6
16.9
17.3
-
-
-
-
8.0
9.7
10.0
8.0
4
16
27
4
0
0
0
0
116
143
128
387
61
87
66
215
7.1
8.9
8.2
7.1
4
16
27
4
0
0
0
0
-
16.5
19.1
17.5
17.7
39.0
91.6
29.3
159.9
98
1.2
0.8
0.6
0.8
75
8.6
10.5
11.2
8.6
4
19
27
4
0
0
0
0
112
135
120
367
56
79
59
194
6.6
6.6
8.5
6.6
4
19
27
4
0
0
0
0
16.6
20.4
16.6
17.8
16.3
19.9
17.1
17.7
46.9
91.0
21.5
159.4
93
-
1.2
6.7
8.5
10.8
6.7
4
16
26
4
0
0
0
0
109
141
123
373
55
85
61
201
Co. Donegal
Glenties
1-10
11-20
21-end
month
21.8
12.6
2.6
37.0
8
7
1
38 16
7
5
1
13
18.3
18.4
18.0
18.2
11.0
12.5
10.7
11.4
14.7
15.5
14.4
14.8
0.7
4.8
11.0
5.8
4.8
4
19
28
4
0
0
0
0
103
110
109
322
Co. Kerry
Ardfert
1-10
11-20
21-end
month
15.8
3.9
33.2
52.9
-
6
4
5
15
5
2
4
11
18.5
21.7
19.0
19.7
11.9
13.4
12.2
12.5
15.2
17.6
15.6
16.1
1.1
9.4
10.8
9.1
9.1
4
17
28
28
0
0
0
0
Co. Leitrim
Ballinamore
1-10
11-20
21-end
month
32.1
5.1
4.0
41.2
9
4
2
62 15
7
1
1
9
19.4
21.7
18.3
19.7
10.8
12.7
11.2
11.6
15.1
17.2
14.8
15.7
1.2
5.2
10.9
8.9
5.2
4
13
28
4
Co. Louth
Ardee
1-10
11-20
21-end
month
18.2
0.8
25.5
44.5
8
2
7
84 17
4
0
3
7
20.1
22.6
18.6
20.4
12.3
14.0
12.2
12.8
16.2
18.3
15.4
16.6
2.0
8.7
11.3
8.9
8.7
Co. Waterford
Dungarvan
1-10
11-20
21-end
month
13.1
1.1
46.4
60.6
-
6
1
6
13
5
1
5
11
19.7
23.7
18.9
20.7
12.3
13.8
13.2
13.1
16.0
18.8
16.1
16.9
1.3
Co. Wexford
1-10 13.8 5
Johnstown Castle 11-20
0.2 1
21-end 112.6 7
month 126.6 222 13
5
0
6
11
18.9
22.1
17.6
19.5
12.3
13.7
13.1
13.0
15.6
17.9
15.4
16.3
1.5
diff. from average
15.4
18.5
15.6
16.4
rain days
wet days
11.4
13.7
12.8
12.6
% of average
19.3
23.3
18.3
20.2
County/
Station
Period
P.E. (mm)
Amount
Soil Moisture (mm)
Deficit Accumulated Surplus
Deficit
Co. Kerry
Valentia Obs.
1-10
11-20
21-end
month
14.9
43.0
26.7
84.6
37
-
14
51
30
16
21
1-10
11-20
21-end
month
9.8
33.8
37.5
81.1
29
32
0
29
61
22
-
Co. Leitrim
Ballinamore
Co. Wexford
Johnstown Castle
1-10
11-20
21-end
month
30.5
39.2
42.7
112.4
5
23
-
68
91
0
99
2.0
3.5
5.3
2.0
4
16
25
4
0
0
0
0
16.6
19.6
17.5
17.9
16.5
19.2
17.7
17.8
4.6
7.4
5.2
4.6
4
17
28
4
0
0
0
0
% of average
-
4
0
4
8
mean 30cm at 0900h
52
76
62
190
6
2
4
122 12
mean 10cm at 0900h
108
132
123
363
19.0
1.2
46.7
66.9
days with ground frost
-
1-10
11-20
21-end
month
date
-
Co. Cork
Fermoy
lowest "grass-min."
-
degree days > 10.0°C
-
degree days > 4.4°C
-
days with air frost
-
date
49 4.2 4 0
54 10.3 18 0
49 3.5 28 0
152 3.5 28 0
lowest min.
70
mean daily
1.8
1.9
2.0
1.9
mean min.
88
period
MEASURED POTENTIAL EVAPOTRANSPIRATION (P.E.)
AND SOIL MOISTURE
SUNSHINE
32.1
84.0
12.1
128.2
Station
mean max.
RAINFALL
amount
10-DAY VALUES FOR SELECTED
AGROMETEOROLOGICAL
STATIONS
total no. of hours
July 2005
-
-
-
SEE BACK PAGE OF JANUARY ISSUE FOR NOTES ON THE DATA
County/
Station
GLOBAL SOLAR RADIATION
P.E.
(MJ/sq. m.)
(Penman)
10-day totals
total for
1-10 11-20 21-end month
total for
month(mm)
Co.Donegal
Malin Head
158.56 146.32 159.48 464.36
61
Co.Dublin
Dublin Airport
162.96 211.68 121.74 496.38
88
Co Kerry
Valentia Obs.
168.29 199.61 161.58 529.48
78
Co.Kilkenny
Kilkenny
164.58 210.09 120.45 495.12
80
Co.Mayo
Belmullet
178.42 148.89 162.66 489.97
69
Co.Monaghan
Clones
146.25 187.18 120.59 454.02
75
Co.Offaly
Birr
146.64 189.28 115.64 451.56
85
8
DIARY
Friday 1st: Dull in the southwest overnight, with rain moving in from the
Atlantic. The cloudy, wet weather pushed northeastwards during the morning
and afternoon, becoming slow-moving over the centre of the country before
moving away eastwards in the evening. Ulster, however, remained largely dry
and had some sunny spells. Winds were southwesterly in direction, generally
light or variable.
Rainfall: nil to 8mm, heaviest at Valentia, nil at Clones and Malin Head
Temperature: max. 16°C to 20°C, min. 8°C to 13°C
Sunshine: nil to 5 hours, sunniest at Belmullet, nil at Valentia
Saturday 2nd: Mist and drizzle in most parts at first. Sunny spells in eastern
areas during the morning. A cold front off the northwest coast moved
gradually northeastwards, bringing rain to western areas by midday. There were
some sunny spells in the west after the passing of the front. Winds were light
southeasterly, increasing to gale force and veering southwesterly with strong
gusts in the north, easing later in the day. Becoming cool.
Rainfall: nil to 5mm, heaviest at Valentia, nil at Malin Head
Sunshine: 2 to 6 hours, sunniest at Dublin Airport, 2 hours at Cork Airport
Sunday 3rd: Showers overnight in western areas. During the late morning
these showers spread gradually eastwards, some of which were very heavy.
Temperatures were a few degrees lower than recently. Winds were westerly in
direction, strong and squally with gale gusts at first, particularly during showers,
but tending to decrease as the day progressed.
Rainfall: 1 to 12mm, heaviest at Mullingar, 1mm at Rosslare
Sunshine: 2 to 11 hours, sunniest at Belmullet, 2 hours at Dublin Airport
Monday 4th: Cool overnight with scattered showers and clear spells. It was a
warm day with well-scattered showers and sunny periods. Temperatures slightly
below normal for the time of year. Cloud began to increase from the
southwest in the evening. Light variable or southwesterly winds overnight
turned more westerly during the day and were moderate at times, before easing
again in the evening.
Rainfall: nil to 1mm, heaviest at Rosslare
Sunshine: 7 to 13 hours, sunniest at Malin Head, 7 hours at Clones
Tuesday 5th: Rain moved into western areas overnight, crossing the country
through the morning and clearing the northeast by mid-afternoon. Showers
followed, some turning heavy during the afternoon, dying out later. Warm and
sunny in the southeast, cooler and cloudier further north and west. Light
winds, increasing to moderate for a time, southerly at first, veering westerly and
then northerly.
Rainfall: 1 to 12mm, heaviest at Clones, 1mm at Malin Head
Sunshine: 1 to 7 hours, sunniest at Rosslare, 1 hour at Valentia
Wednesday 6th: Spots of rain and drizzle during the night, mainly in the
western half of the country. More widespread light, showery rain developed in
the late morning and afternoon, drying up again by evening. Cool. Some breaks
in the cloud in the south and east, though mainly cloudy. Winds were
moderate, northwesterly in direction.
Rainfall: nil to 3mm, heaviest at Mullingar
Sunshine: nil to 5 hours, sunniest at Valentia and Malin Head, nil at Belmullet
Thursday 7th: Cloudy overnight with patchy rain and drizzle, and mist in
places also. Continuing cloudy through the morning and afternoon with rain
and showers in places. By evening the rain and drizzle were confined to the
north and northwest and it was mainly dry over the rest of the country. Fog
developed in places late in the night. Light northwesterly winds throughout.
Rainfall: nil to <1mm generally, 3mm at Mullingar
Temperature: max. 15°C to 19°C , min. 11°C to 13°C
Sunshine: nil to 1 hour, sunniest at Valentia
Friday 8th: Rain, drizzle and fog overnight and through the morning. It
became mainly dry during the afternoon, although it continued damp in the
northwest. Warm and humid. It remained mostly overcast with just the odd
sunny break, mainly in the south and east. Winds were light, northwesterly in
direction.
July 2005
Rainfall: nil to 5mm, heaviest at Belmullet, nil at Valentia and Rosslare
Sunshine: nil to 1 hour, sunniest at Dublin Airport
Saturday 9th: Damp and humid overnight with spots of drizzle and patches
of fog. The drizzle became persistent for a while in the east during the
morning. By afternoon it was dry countrywide and remained so for the rest of
the day. Warm with long spells of sunshine in parts of the southeast and
southwest, but duller elsewhere. Winds were light, northwesterly or variable.
Rainfall: nil to 1mm, heaviest at Casement Aerodrome
Sunshine: nil to 12 hours, sunniest at Rosslare and Valentia, nil at Dublin Airport
Sunday 10th: Early mist and fog cleared during the morning, leading to a very
warm, dry and sunny day generally. The extreme north remained foggy and
cloudy, however, with occasional drizzle in the morning. Afternoon
temperatures were well above normal in inland areas but slightly lower near
coasts due to onshore breezes. Winds were light and variable.
Rainfall: nil to trace
Sunshine: 9 to 15 hours generally, 1 hour at Malin Head, 15 hours at Rosslare
Monday 11th: Very mild and humid overnight with mist and fog patches. Any
mist or fog soon cleared to give a very sunny day with temperatures well above
normal inland, but it was slightly cooler on coasts due to sea breezes. Very mild
again after dark with fog returning to northwestern coastal areas. Winds were
light and variable.
Rainfall: nil
Temperature: max.19°C to 29°C, min. 12°C to 16°C
Sunshine: 11 to 15 hours, sunniest in the east, 11 hours at Malin Head
Tuesday 12th: Early mist and fog cleared during the morning and most areas
had another hot and sunny day with temperatures well above normal. Some
thundery showers in Munster and Leinster. The northwest remained cloudy
with some patchy drizzle and very little sunshine. Winds were light variable.
Rainfall: nil generally, up to 25mm locally in showers
Sunshine: 9 to 15 hours generally, trace at Malin Head, 15 hours at Rosslare
Wednesday 13th: Continuing very warm. Some drizzle or light rain over the
west and northwest during the night, otherwise mainly dry. Becoming dry
during the day in the northwest but remaining cloudy. Warm and sunny in most
places and continuing very mild and humid during the evening with
temperatures well above normal. Winds were light variable or northeasterly.
Rainfall: nil to 2mm, heaviest at Malin Head
Temperature: max.17°C to 26°C, min. 12°C to 16°C
Sunshine: <1 to 10 hours, sunniest at Valentia, <1 hour at Belmullet
Thursday 14th: A mostly cloudy day with spells of hazy sunshine and some
rain or drizzle in the morning along Atlantic coasts. More organised rain
moved into the northwest in the afternoon and pushed slowly southeastwards.
Generally sunny in southern coastal regions. Cooler than of late. Light to
moderate southwesterly winds, fresh and gusty at times in the northwest.
Rainfall: nil to 3mm, heaviest at Malin Head
Sunshine: nil to 11 hours, sunniest at Rosslare nil at Valentia
Friday 15th: Mild overnight, then becoming warm in the southern half of the
country. Cooler further north with cloud persisting in Connacht and Ulster.
Generally dry with just a little light rain in the southwest. Winds were light,
west or northwesterly in direction.
Rainfall: nil to trace generally, 1mm at Valentia
Sunshine: nil to 12 hours, sunniest at Cork Airport, nil at Malin and Belmullet
Saturday 16th: Dry with sunny periods in most parts, although cloudy in the
northwest and north where cloud persisted for most of the period. Very warm
with temperatures above normal generally with the exception of northern
areas. Warm and dry also during the evening. Winds were light, variable or
westerly to northwesterly in direction.
Rainfall: nil
Sunshine: nil to 14 hours, sunniest Rosslare, nil at Malin Head
July 2005
DIARY
Sunday 17th: Early fog, quite dense in parts, cleared during the morning to
give a dry day with sunny periods in most places. Very warm with temperatures
up to or above normal. During the afternoon, cloud with rain and drizzle
approached the west coast, extending slowly eastwards. Very sunny in the
southeast while the northwest remained overcast. Winds were south to
southwesterly, generally light, but stronger in western regions at times.
Rainfall: nil to 5mm, heaviest at Belmullet
Temperature: max. 18°C to 25° min. 11°C to 15°C
Sunshine: nil to 15 hours, sunniest at Cork Airport, nil at Belmullet
Monday 18th: Scattered light showers throughout the day, dying back to
western coasts towards evening. Broken cloud gave sunny breaks in most areas,
though somewhat cloudier in the southwest. Temperatures were down on
recent values. Winds were west to southwesterly, fresh or occasionally strong.
Rainfall: nil to 5mm, heaviest at Malin Head, nil at Rosslare
Sunshine: 3 to 10 hours, sunniest at Dublin Airport, 3 hours at Valentia
Tuesday 19th: Clear spells in the east and southeast, while further west there
were frequent showers that passed quickly in the fresh winds. More persistent
rain in the southwest during the afternoon, although amounts were quite small.
Some sunny spells in the east and southeast during the evening. Winds were
westerly in direction, light to moderate generally but stronger near western
coasts.
Rainfall: nil to 2mm, heaviest at Valentia
Temperature: max. 15°C to 21°C, min 10°C to 14°C
Sunshine: trace to 9 hours, sunniest at Rosslare, trace at Valentia
Wednesday 20th: Early rain in the midwest and drizzle in western areas at
first, with clear spells in the east and south. The rain became lighter during the
late morning and eventually died out during the late afternoon. The south,
southeast and east had a mainly dry day with sunny spells in the afternoon.
Winds, generally northerly in direction, slackened as the day progressed.
Rainfall: nil to 1mm generally, 8mm at Birr
Sunshine: nil to 8 hours, sunniest at Dublin Airport, nil at Belmullet
Thursday 21st: A dull morning with patches of rain or drizzle and only short
sunny spells. Fog along the west coast. The afternoon and evening were drier
and brighter with some sunny spells in places. The rain and drizzle returned to
the northwest in the evening with fog patches in the southwest. Light to
moderate northwesterly winds decreased to light by late afternoon.
Rainfall: nil to 1mm, heaviest at Dublin Airport
Sunshine: nil to 9 hours, sunniest at Cork Airport, nil at Belmullet
Friday 22nd: A cloudy day generally with mist and drizzle, particularly in
western areas. A few sunny spells in places, mainly in the southeast and
midlands. By mid-afternoon a frontal system had reached the southwest,
resulting in some heavy showers as it moved northeastwards. Winds were light,
northerly in direction.
Rainfall: nil to 6mm, heaviest at Shannon Airport
Sunshine: nil to 3 hours, sunniest at Rosslare and Mullingar
Saturday 23rd: An overcast start to the day in most parts with heavy showers
in the midlands. A few sunny spells but generally dull. By early afternoon the
showers had reached most areas apart from the extreme north. Heavy rain
moved into the southwest by early evening and spread northeastwards over the
country. Winds were light to moderate, east to southeasterly.
Rainfall: nil to 28mm, heaviest at Valentia, nil at Malin Head
Sunshine: nil to 1 hour, sunniest at Rosslare
Sunday 24th: Rain in Munster and south Leinster overnight was very heavy
and persistent along the south coast. Mainly dry elsewhere with mist. The rain
moved slowly eastwards during the day and only cleared the east coast by late
afternoon. Again it was heavy and persistent and southern coastal regions fared
worst, leading to localised flooding. Drier weather with a few sunny spells
followed into the southwest in the evening. The northern half of the country
had a dry day with sunny periods. Winds were east to northeasterly, moderate
to fresh with occasional gusts.
Rainfall: nil to 66mm, heaviest at Cork Airport, 52mm at Rosslare,
9
nil at stations north of Mullingar
Sunshine: nil to 13 hours, sunniest at Connacht Airport
Monday 25th: Remaining patches of rain cleared the southeast early in the
night. It remained mostly dry countrywide for the rest of the day, the only
exceptions being some light drizzle near northwestern coasts during the
morning and isolated showers in the south late in the evening. Long spells of
sunshine in the southeast and the southwest, cloudy elsewhere with short
sunny breaks. Winds were light, northerly or variable, moderate in the
northwest for a while in the afternoon.
Rainfall: nil generally, <1mm at Cork Airport
Sunshine: trace to 9 hours, sunniest at Rosslare, trace at Birr and Mullingar
Tuesday 26th: Dry and clear during the night with slack winds. Remaining dry
and fine for the rest of the period. Long sunny periods in the south and east of
the country, however it was cloudier over the rest of the country with very little
sunshine in the extreme north. Temperatures were near normal. Light north to
northwesterly winds.
Rainfall: nil
Sunshine: <1 to 14 hours, sunniest at Valentia, <1 hour at Malin Head
Wednesday 27th: Dry and cool during the night with just a little drizzle in
western and northwestern areas. Dry during the day with variable cloud
amounts; most sunshine in northern and eastern areas. Northeasterly winds
kept temperatures around or a little below normal. Remaining dry during the
evening, but cool. Winds were northeasterly, generally light but fresher along
the southeast coast.
Rainfall: nil to trace generally, 1mm at Rosslare
Sunshine: nil to 14 hours, sunniest at Malin Head
Thursday 28th: Persistent rain overnight in the southeast spread further
north by morning, affecting the eastern half of Leinster. The rain continued to
spread slowly northwards during the afternoon, affecting eastern parts of
Ulster. Overcast in the east and north, some sunny breaks in the south, long
spells of sunshine in the west. Dry in Connacht and Munster. North or
northeasterly winds were strongest on the east coast and light, occasionally
moderate, elsewhere.
Rainfall: nil to 35mm, heaviest at Rosslare and Dublin Airport
Sunshine: nil to 12 hours, sunniest at Belmullet, nil in the east
Friday 29th: Cloudy with intermittent moderate rain in central, eastern and
southeastern areas, while the Atlantic coast had broken cloud with some clear
spells at times. Outbreaks of rain affected most areas except the extreme
northwest, which remained dry with sunny spells. A cool day with temperatures
below normal almost everywhere. Light northerly winds.
Rainfall: nil to 24mm, heaviest at Dublin Airport, nil at Malin Head
Sunshine: nil generally, 5 hours at Belmullet
Saturday 30th: A slow-moving front over the country weakened in a
northerly airflow. Mostly cloudy throughout with patchy rain and drizzle during
the day. No sunshine except in the extreme southwest. The rain and drizzle
died out by evening in all areas except along eastern coasts. Light, north to
northwesterly winds throughout the period.
Rainfall: nil to 6mm, heaviest at Casement Aerodrome, nil at Cork Airport
Sunshine: nil generally, 1 hour at Valentia
Sunday 31st: A dry start to the day in most parts with just occasional light
showers in the midlands. By late morning, showers off the east coast moved
inland, to give some heavy falls in eastern counties. Cloudy over most of the
country apart from the southwest and north. By early evening most of the
showers had died out. Winds were light, northerly in direction.
Rainfall: nil to 2mm, heaviest at Dublin Airport
Sunshine: nil to 1 hour generally, 7 hours at Valentia, 5 hours at Malin Head
10
Wettest July on
record at
Rosslare, but dry
over northern half
It was a dry month over most of
the northern half of the country,
but heavy falls on individual
days brought totals well above
normal near eastern,
southeastern and southern
coasts. Totals ranged from
24mm at Malin Head, where it
was the driest July since 1983, to
127mm at both Rosslare and
Johnstown Castle, Co. Wexford;
Rosslare’s total was its highest
for July since records began
there in 1956. Percentage of
normal values were between 34%
at Malin Head and 249% at
Rosslare.
After spells of rain in all areas
during the first week, there
followed mainly dry weather for the
remainder of the month.
Exceptions were coastal areas of
Munster and Leinster, however,
where some torrential falls were
measured in the periods 23rd/24th
and 28th/29th. Cork Airport’s fall
of 73.2mm on the 23rd was its
highest daily fall for July since 1975,
while the highest July falls for more
than 30 years were measured at
some other stations. The rainfall
recording station at Bohernabreena
(Castlekelly), Co. Dublin, recorded
a 24-hour fall of 95.7mm on the
28th, with a total of 146mm falling
there in the 48-hour period
28th/29th. The total number of
wetdays (days with 1mm or more of
rainfall) during the month was near
or below normal everywhere,
however, ranging between 9 and 13
wetdays generally.
RAINFALL
County/
Station
July 2005
Total
% of
Amount 1961-90
(mm) average
CO. CLARE
SHANNON AIRPORT
43.9
CARRON
89.8
CO. CORK
FERMOY (MOORE PARK)
66.9
CORK AIRPORT
105.2
SHERKIN ISLAND
66.9
94.2
CO. DONEGAL
MALIN HEAD
24.3
BALLYSHANNON(CATHLEEN'S FALL) 46.6
GLENTIES
37.0
CO. DUBLIN
DUBLIN (PHOENIX PARK)
72.1
DUBLIN AIRPORT
83.9
CASEMENT AERODROME
79.2
DUBLIN (MERRION SQUARE)
88.0
CO. GALWAY
GALWAY (UNIV.COLL.)
46.6
MAAM VALLEY
80.6
CONNEMARA NATIONAL PARK
68.1
BALLYGAR
45.6
CO. KERRY
71.7
ARDFERT (LISCAHANE)
52.9
CO. KILKENNY
KILKENNY
55.0
CO. LEITRIM
BALLINAMORE
41.2
CO. LIMERICK
MOUNT RUSSELL
117.9
CO. LOUTH
ARDEE (BOHARNAMOE)
44.5
CO. MAYO
BELMULLET
32.3
STRAIDE
29.6
CONNACHT AIRPORT
41.0
CO. MEATH
WARRENSTOWN
79.3
CO. MONAGHAN
CLONES
46.5
CO. OFFALY
BIRR
84.6
DERRYGREENAGH
58.4
CO. SLIGO
ARDTARMON
39.4
CO. TIPPERARY
67.1
CO. WATERFORD
WATERFORD (TYCOR)
80.6
60.6
CO. WESTMEATH
MULLINGAR II
67.3
CO. WEXFORD
JOHNSTOWN CASTLE
126.6
ROSSLARE
126.8
95.5
90.6
Number of
Raindays Wetdays
Most in
a day / date
(>0.2mm) (>1mm)
77
93
11.3
26.9
23
22
17
18
12
14
122
162
115
39.4
73.2
40.5
65.0
23
23
23
23
12
12
9
13
8
10
7
8
34
64
38
6.7
14.4
5.2
17
4
17
13
15
16
9
11
13
144
29.0
37.8
33.7
29.4
28
28
28
28
18
16
17
14
10
8
11
8
14
16
16
17
10
11
13
11
169
205
69
74
74
9.7
14.9
9.1
16.3
4
23
4
3
98
36.1
26.8
23
23
15
15
10
11
104
17.3
23
17
11
62
12.0
4
15
9
39.6
23
23
16
84
15.2
28
17
7
48
47
6.2
4.5
7.1
4
7
4
16
18
17
9
11
14
142
26.2
28
15
9
78
8.4
28
15
10
143
101
19.7
14.7
22
3
19
15
15
11
8.3
4
16
11
23.6
23
19
11
144
34.7
27.0
23
23
16
13
9
11
110
17.5
28
15
12
222
249
168
35.5
30.8
32.4
26.1
23
24
23
23
13
12
18
16
11
9
13
11
11
RAINFALL
July 2005
Total rainfall (mm)
Percentage of normal rainfall
Daily 0-24h rainfall values (mm)
27.9
25
32.6
20
15
10
5
0
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
Dublin Airport
Clones
12
TEMPERATURE
Warmer than normal
everywhere
July 2005
+1.0°C
+0.4°C
SCALE
Mean air temperatures for the month were
around a degree higher than normal generally
and were up to two degrees above normal in
places. The month was notable for a spell of hot
weather in almost all areas between the 10th and
12th, when temperatures reached close to 30°C in
places. Mean temperatures ranged from 14.4°C at
Connacht Airport to 17.3°C at Waterford (Tycor)
and it was the warmest July since 1999 at several
stations.
The first half of July was much warmer than the
second, especially the period between the 9th and
14th. Many stations recorded their highest maximum
temperatures for July since 1989 on either the 11th or
12th. At Kildalton (Piltown), Co. Kilkenny, maximum
temperatures exceeded 30°C on both of these days,
with its highest value of 30.3°C measured on the
12th. Maximum temperatures were much closer to
normal during the second half of the month,
however. There was less variation through the month
in minimum air temperatures, although cooler
weather prevailed at the beginning and end of the
month. The lowest air temperature, 3.8°C, was
-1.0°C
+1.0°C
+1.2°C
+0.9°C
+1.0°C
+0.9°C
+1.3°C
+0.5°C
+1.1°C
+0.9°C
+1.0°C
Mean Temperature
(difference from 1961-90 normals)
measured at Straide, Co. Mayo, on the 4th, while the
lowest grass minimum value, -3.2°C, was recorded at
Derrygreenagh, Co. Offaly, on the same day.
Daily 0-24h maximum temperatures (°C)
30
25
20
15
10
1
2
3
4
5
Valentia
6
7
8
Observatory
9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31

Dublin Airport
z Clones
Daily 0-24h minimum temperatures (°C)
20
15
10
5
0
1
2
3
4
Valentia
5
6
7
8
Observatory
9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31

Dublin Airport
z Clones
County/
Station
CO. CLARE
SHANNON AIRPORT
CARRON
CO. CORK
FERMOY (MOORE PARK)
CORK AIRPORT
SHERKIN ISLAND
CO. DONEGAL
MALIN HEAD
BALLYSHANNON(CATHLEEN'S FALL)
GLENTIES
CO. DUBLIN
DUBLIN (PHOENIX PARK)
DUBLIN AIRPORT
CASEMENT AERODROME
DUBLIN (MERRION SQUARE)
CO. GALWAY
GALWAY (UNIV.COLL.)
MAAM VALLEY
CONNEMARA NATIONAL PARK
BALLYGAR
CO. KERRY
ARDFERT (LISCAHANE)
CO. KILKENNY
KILKENNY
CO. LEITRIM
BALLINAMORE
CO. LIMERICK
MOUNT RUSSELL
CO. LOUTH
ARDEE (BOHARNAMOE)
CO. MAYO
BELMULLET
STRAIDE
CONNACHT AIRPORT
CO. MEATH
WARRENSTOWN
CO. MONAGHAN
CLONES
CO. OFFALY
BIRR
DERRYGREENAGH
CO. SLIGO
ARDTARMON
CO. TIPPERARY
CO. WATERFORD
WATERFORD (TYCOR)
CO. WESTMEATH
MULLINGAR II
CO. WEXFORD
JOHNSTOWN CASTLE
ROSSLARE
13
TEMPERATURE
July 2005
°C
Mean/ deviation
Mean from 1961-90
min.
average
Highest
max./date
Lowest
min./date
19.8
18.8
12.7
11.8
16.3
15.3
0.5
1.1
28.0 11
26.2 11
8.5
7.1
20.2
19.3
19.0
20.2
12.6
12.5
13.3
11.6
16.4
15.9
16.2
15.9
1.2
1.0
1.3
28.4
26.2
24.3
28.0
16.3
18.2
18.2
12.2
12.5
11.4
14.3
15.4
14.8
0.4
0.8
0.7
22.0 2
25.1 11
23.2 10
19.6
19.3
19.9
19.5
12.3
11.9
12.2
14.4
16.0
15.6
16.1
17.0
0.9
25.8
24.8
27.3
24.2
11
11
12
12
8.6 27
8.5 27
8.3 4
10.9 4
20.4
19.7
18.0
20.4
13.0
12.3
11.1
11.9
16.7
16.0
14.6
16.2
1.4
29.0
28.1
24.0
28.0
11
11
11
11
18.3
19.7
13.2
12.5
15.8
16.1
0.9
1.1
20.8
12.5
16.7
19.7
11.6
15.7
19.1
12.1
15.6
20.4
12.8
16.6
17.4
19.4
17.7
12.7
11.8
11.1
19.6
Mean
max.
0
0
0
0
6.7 4
7.4 4
9.5 16
6.4 4
2.0 4
4.7 4
6.3 16
3.6 3
0
0
0
0
0
0
0
0
8.1 4 27
7.5 28
4.8 4
6.2
0
0
0
0
3.6 27
2.9 27
4.4 27
0
0
0
0
0
0
0
8.9 4
8.1 4
7.5 26
6.2 4
3.7
5.2
5
4
0
0
4.5
4
0
0
0
0
26.2 12
27.6 11
9.7 27
9.1 28
6.0 27
4.6 4
0
0
0
0
1.3
29.2 11 12
6.8
4
1.2
4
0
0
1.2
28.6 11
5.2
4
-1.1
4
0
1
27.9 11
7.8
4
5.2
4
0
0
2.0
29.0 11
8.7
4
6.7 28
0
0
15.1
15.6
14.4
1.0
1.0
23.6 11
27.8 11
25.9 11
10.5 28
3.8 4
6.3 4
8.8 28
-1.0 4
3.9 4
0
0
0
0
2
0
12.2
15.9
1.0
26.8 11
8.0
4
6.8
4
0
0
19.5
12.1
15.8
1.2
28.6 11
6.3
4
3.6
4
0
0
19.8
20.1
12.2
11.9
16.0
16.0
0.9
1.3
28.4 11
27.9 11
7.1
6.6
4
4
3.2 25
-3.2 4
0
0
0
1
19.3
12.3
15.8
25.7 11
8.6
4
6.0
4
0
0
19.9
12.4
16.2
28.7 12
7.8
4
4.5
4
0
0
21.2
20.7
13.3
13.1
17.3
16.9
1.8
1.3
28.4 11
27.7 12
6.6
8.0
4
4
7.1
4
0
0
0
19.2
11.9
15.6
0.9
27.2 11
7.3
4
4.4
4
0
0
19.5
18.6
20.1
19.7
13.0
13.7
12.8
11.8
16.3
16.2
16.5
15.8
1.5
1.1
1.4
23.8
22.0
27.0
28.0
8.6
8.5
9.2
7.1
4
4
4
4
6.6
6.4
8.4
3.1
4 19
4
1
4
0
0
0
0
0
0
0
0
1.0
0.7
12
14
12
12
4.6
2.7
Days with
air frost ground frost
4
4
12
12
12
11 12
4
4
Lowest
grass min./date
4
3.5 28
0
0
14
SUNSHINE
County/
Station
Daily mean
(hours/day)
CO. CLARE
SHANNON AIRPORT
CO. CORK
FERMOY (MOORE PARK)
CORK AIRPORT
SHERKIN ISLAND
CO. DONEGAL
MALIN HEAD
BALLYSHANNON(CATHLEEN'S FALL)
CO. DUBLIN
DUBLIN AIRPORT
CASEMENT AERODROME
CO. GALWAY
GALWAY (UNIV.COLL.)
CO. KERRY
ARDFERT (LISCAHANE)
CO. KILKENNY
KILKENNY
CO. LEITRIM
BALLINAMORE
CO. MAYO
BELMULLET
STRAIDE
CONNACHT AIRPORT
CO. MONAGHAN
CLONES
CO. OFFALY
BIRR
CO. WATERFORD
CO. WESTMEATH
MULLINGAR II
CO. WEXFORD
JOHNSTOWN CASTLE
ROSSLARE
% of
% of
average possible
Most in
a day/date
4.58
100
28
14.4 11
4.14
5.39
6.31
5.30
88
100
109
26
33
39
13.2
15.1
14.8
14.7
3.25
3.60
76
90
19
22
13.8 27
14.0 11
4.92
4.65
92
94
30
28
15.6 11
15.5 11
5.00
108
30
13.9 11
5.35
4.31
118
33
26
15.0 11
13.0 11
4.29
92
26
14.8 11
3.86
93
23
12.3 12
17
11
10
11
July 2005
Dull except in south
and southwest
July sunshine totals were below normal at
most stations, but totals were near or a
little above normal in the south and
southwest. They ranged from 101 hours at
Malin Head, where it was the dullest July
since 1998, to 196 hours at both Rosslare
and Sherkin Island, Co. Cork. Percentage
of normal values were between 76% of
normal at Malin Head and 118% at
Valentia Observatory.
As shown by the chart below, there were
spells of sunny weather during the month,
separated by dull periods. The highest daily
value, 15.6 hours, was recorded at both
Rosslare and Dublin Airport on the 11th; at
Dublin, this was its highest daily sunshine on
record for July. Global solar radiation totals
ranged between 91% of normal at Clones
and 102% at Valentia Observatory.
150%
76%
SCALE
3.63
4.04
3.71
85
22
12.4 11
13.4 11
13.0 24
50%
85%
3.93
92
24
14.1 11
3.34
79
20
12.4 11
5.16
98
32
12.8 10 11
4.29
94
26
15.0 11
5.14
6.31
4.98
5.22
93
100
97
32
39
31
14.5 11
15.6 11
12.9 11 17
14.8
92%
94%
79%
100%
94%
92%
100%
118%
100%
Total Sunshine
(difference from 1961-90 normals)
Daily sunshine values(hours)
16
14
12
10
8
6
4
2
0
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
Dublin Airport
Clones
15
WORLD WEATHER
July 2005
%
JULY RAINFALL
(percentage of
1961-1990 normal)
200
150
125
100
75
50
0
°C
+5
+3
JULY MEAN TEMPERATURE
(difference from
1961-1990 normal)
+1
-1
-3
-5
Southwestern USA was affected by
a severe heatwave during mid-July.
Maximum temperatures above 40°C
were recorded across parts of
Nevada, California, Arizona and
southern Utah; Las Vegas measured
47.2°C on the 19th, equalling its
previous highest value in July 1942.
Death Valley had 6 consecutive days
with temperatures above 51.7°C. At
least 13 deaths were blamed on the
extreme conditions in Arizona. The
heatwave then spread to the east
coast during the final week.
Global weather
highlights of
the month
Data supplied by NOAA
Climate Prediction Centre,
US Department of Commerce
Severe thunderstorms over Britain on the afternoon of
the 28th produced a tornado that struck the city of
Birmingham. The tornado damaged buildings and cars,
uprooted trees and tore roofs off houses in an area south
of the city centre. There were 23 injuries but no fatalities.
Heat and drought affected much
of western Europe during July.
In France, water rationing was
in place throughout half of the
country, with western areas the
most acutely affected by
drought. In Spain and Portugal,
the worst drought conditions
since the late 1940s persisted,
with 97% of Portugal affected
by severe to extreme drought.
Flooding affected the northeastern part of Romania during
the first half of July, with 30 fatalities reported along with
destruction of more than 2300 homes. The flooding was
reportedly the worst in 30 years, with preliminary damage
estimates of 1 billion euro. This was the second major
flooding event of the year (see MWB of May). In addition,
flooding affected adjacent areas of Bulgaria, continuing a
period of very wet weather there since last month.
16
FEATURE
July 2005
July 1955 was the sunniest month on record
Fifty years ago this month, high pressure over
Ireland produced the sunniest and also one of the
driest months on record, particularly over
southern areas. A large blocking anticyclone in
the eastern Atlantic persisted for almost all of July
1955, steering low pressure systems well to the
north of the country (see chart on right). Valentia
Observatory’s sunshine total of 308.3 hours of
sunshine- an average of almost 10 hours per dayremains the highest monthly total ever recorded
in Ireland, while it was also the sunniest month
on record at both Dublin Airport and Birr.
Rainfall totals of less than 10mm were measured
at many southern and eastern stations, with totals
of only 1 or 2mm in parts of Cork. At almost all
stations, there were only between 1 and 3 wetdays
during the month (days with 1mm or more
rainfall); around 90% of the monthly fall generally
was recorded on the 2nd alone. Mean air
temperatures overall were around two degrees
above normal, with maxima reaching over 25°C
on several days and up to 29°C on the 8th.
Percentage of
normal rainfall,
July 1955
%
>100
75 - 100
50 - 75
25 - 50
12.5 - 25
<12.5
16
14
12
10
8
6
4
2
0
Daily sunshine values, July 1955
1
2
3
4
5
6
7
- Valentia Observatory
8
Synoptic chart at 1200UTC on 26th July 1955
Ireland was not alone in experiencing unusually dry
and sunny weather that month. A prolonged heatwave
over much of the United States produced record
temperatures that in some places have not been
exceeded to the present. In the Los Angeles area, a
total of 946 deaths was attributed to the effects of
extreme heat during the month, with values rising
close to 44°C at times. A maximum temperature of
32.7°C was recorded in Norway early in the month,
while 31.1°C was observed in the London area on the
18th. The monthly sunshine total of 354.3 hours at
Dale Fort in Dyfed remains the highest of any month
on record in Wales. Ironically, however, during a
month when rainfall totals generally were extremely
low, July 1955 also holds the record in Britain for the
highest 24-hour rainfall total. This was measured at
Martinstown in Dorset, when 279mm of rain fell
during spells of intense thunderstorm activity on the
18th; flooding washed away roads and houses in the
Dorchester and Weymouth areas. In Ireland, the fine
summer weather extended into most of August also,
which was warm, sunny and generally dry.
9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
- Dublin Airport
- Clones