[Duncan Railton]

A very confused month - cold in the first half and very warm for the last third...

RF 43.3
Avg hPa 1011
Max hPa 1023
Min Hpa 998
Max 26.8
Min -0.8
Min Max 6.7
Max Min 14.4
Avg.Max 16.2
Avg Min 7.9
AVG 12.03

9 days over 20C in succession and 4 over 25C makes it a notable May warm spell (my best), but the start of the month was drastically below average.

[Dave K]

Whilst both temperature and rainfall ended up as near average in these site records, that belies the fact that this was a month of extremes. The first 10 days were cold and wet, with the early May Day Bank Holiday weekend especially dismal, the 6th having the coldest daytime temperature for a May day in these records. A run of 4 consecutive May days with the daytime high temperature not reaching 10 °C was an unwelcome first. The last 9 days of the month however balanced this with the longest May spell of hot weather in these records - 6 consecutive days reached 25 °C or higher. Virtually all the month's rain fell in the first half of the month but at 45.7 mm was only a fraction above average. Sunshine ended at about 85% of average, the first 10 days were very dull but the 22nd - 28th was a very sunny spell.




Full daily stats at http://www.tonbridge...012/2012-05.htm

[Richie]

---------------------------
MAY 2012 Extremes:-
---------------------------
SCREEN TEMPERATURES:-
Minimum Air Temp: 1.4°c ---- Day 07
Maximum Air Temp: 21.2°c ---- Day 10
Lowest Maximum: 9.8°c ---- Day 04
Highest Minimum: 11.9°c ---- Day 31
Mean Maximum: 15.2°c
Mean Minimum: 7.4°c
Mean: 11.3°c

Minimum Grass Temp: -0.7°c ---- Day 07
---------------------------------------------------------
RAINFALL:-
Highest Rainfall in 24 hours: 16.5mm ---- Day 31
Total Rainfall for the Month: 48.6mm
Days with Rain >0.2mm: 3 Days.
Days with Rain >1.0mm: 7 Days.
----------------------------------------------------------
BAROMETRIC PRESSURE:-
Air Pressure Maximum: 1039.2 mb ---- Day 12
Air Pressure Minimum: 1001.2 mb ---- Day 10
Mean (0900 UTC): 1018.1 mb.
----------------------------------------------------------
RELATIVE HUMIDITY:-
RH Max: 100%
RH Min: 58%
Mean RH (0900 UTC): 79%
----------------------------------------------------------
SOIL TEMPERATURE:- (30cm Depth)
Soil Max: 14.9°c
Soil Min: 8.3°c
Soil Mean: 11.6°c
------------------------------------
WIND DIRECTION:-
N: 6
NE: 4
E: 7
SE: 0
S: 1
SW: 3
W: 2
NW: 6
CALM: 2

Mean Wind Speed: 21.0 MPH

Maximum Wind Gust: 28.5 MPH ---- Day 13
----------------------------------
Days with:-

Air Frost: 0
Ground Frost: 2
Fog/Mist: 2
Thunder/Lightning: 0
Snow Falling: 0
Snow Lying: 0
Sleet: 0
Hail: 0
Gale: 0
Ice Days: 0

[ole blue eyes 1944]

Station Statistics for May 2012 AWS Burncross, Sheffield, South Yorkshire UK

TEMPERATURE

17.0 Mean Max c
-1.3 Diff from Average
7.9 Mean Min c
+0.8 Diff from Average
12.0 Mean c
-0.5 Diff from Average
28.6 High Max c 28th
9.2 Low Max c 5th
14.2 High Min c 31st
-0.6 Low Min c 6th
-2.2 Grass Min c 6th


RAIN

41.6 Rain Total (mm)
72 % of Average
3 Wet days with >0.2 mm
5 Wet days with >1.0 mm
18.4 Most Rain in a day 9th

NUMBER OF DAYS WITH.

1 Air frost (air min temp -0.1C or less)
4 Ground Frost (grass min temp -0.1C or less)
0 Sleet/Snow Falling
0 50% snow cover at morning observation hour
0 Thunder Heard
0 Small hail (<5mm diameter)
0 Large Hail (>=5mm diameter)
0 Fog at morning observation hour


SUNSHINE

177.53 Total Sunshine (hours)
112% of Average
15.50 Most in a day (hours)
26th Day of Most Sun
2 Sunless Days


WIND

0 Days with gale (10 min mean wind 39 mph or more)

Wind Direction number of days with wind from.

10 N
4 NE
2 E
2 SE
0 S
2 SW
6 W
5 NW
0 Calm

WIND GUST

Mean Wind Speed 8.4mph
Maximum Gust 35.0 mph
Day of Max Gust 11th, 13th, 25th


THUNDER EVENTS

None

OTHER MEASUREMENTS

52 Cloud Cover %
57 Mean Relative Humidity % (Taken at Morning Observation)
1014 Mean Pressure (mb) at 9:00 am GMT only
1038 Max pressure at any time of day 12th
998 Min pressure at any time of day 10th

STATION NOTES.

May commenced in cold conditions which apart from a warm day on the 10th where 21.8c was recorded as a maximum then as forecast on the 22nd the warm spell began and lasted until the 30th culminating in a maximum of 28.6c on the 28th. Two cold nights occurred on the 5th +1.1c and the 6th -0.6c as minimum air temperatures.

Rainfall again was below average 72% a total of 41.6 mm with most of the rain 18.4 mm recorded on the 9th. Pressure was low on the 10th with a measurement of 998 mb at 09z.

From the 22nd onwards some outstanding sunshine figures were recorded 22nd, 14.81 hours, 23rd, 12.89, 24th, 12.87 hours, 25th 13.25 hours 26th 15.50 hours 27th 15.39 hours, 28th 9.39 hours and the 29th 10.07hors. This gave a total of 177.53 hours sunlight within the month.

[Les]

Here is are the readings from my site in rural Midlothian.



SUMMERY

It was largely rather cold for the first three weeks of the month with frequent days with recordable rain.There were 7 days with single figure maxmas in the first three weeks with some night air frosts (severe on the 5th).It only warmed up from the 22nd onwards but on the final two days the warm spell tailed off with rain and fog ,though it was dry from the 20th to the 29th inclusive.Pressure was quite high.The wettest day was on the 10th with 18.9mm,the 2nd wettest on the 31st with 12.3mm.

TEMPERATURES

Highest.............................23.0C on the 28th
Lowest..............................-3.6C on the 5th
Lowest Max...........................5.8C on the 10th
Highest Min.........................10.3C on the 24th
Mean Max............................14.40C
Mean Min.............................3.30C
MEAN.................................8.85C

WEATHER
days with...
Rain(1.0mm+)............................12
Fog......................................6
Thunder..................................0
Hail.....................................0
Air Frosts...............................7
Rainfall.................................68.1mm

PRESSURE

Highest...............................1035mbs on the 12th
Lowest................................1004mbs on the 7th and 8th
MEAN..................................1019.5mbs

[HSEA2]

Some bits from the Meteogroup summary published in the Guardian

http://www.guardian....e?newsfeed=true

Highest Mean Maximum: 18.2c at Southampton
Lowest Mean Maximum: 9.3c at Fair Isle

Highest Temperature: 29.0c at Cromdale (27th) (although met office says Achnagart at 29.3c was higher)
Lowest Temperature: -6.2c at Saughall (5th) (had this occurred one day later it would have constituted a date record)

Highest Rainfall: 157mm at Kinlochewe
Lowest Rainfall: 8mm at Manston

Sunniest: 270 hours at Tiree
Dullest: 152 hours at Hampstead-London, Wattisham-Suffolk and Monks Wood-Cambridgeshire.

[BUTTERFLY]

Had the late May hot spell not been as marked, but a more normal late May warm spell, I expect quite a lot of stations in Scotland and perhaps elsewhere would have ended up cooler in May than in March 2012; however at present the only example I can find is Baltasound in Shetland, where the mean for March 2012 was 7.3 deg. C. and the mean for May only 7.1 deg. C. - see http://www.met.readi...ge/Mar2012.html and http://www.met.readi...ugge/PREV.html. However I think the great majority, possibly all or nearly all, though I have not time to check, of sites were warmer in March 2012 than in April; the last time this happened generally was in 1998 I believe.