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DECEMBER
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‡ SUN: Sunshine hours are calculated approximately and solely from solar radiation readings, but note that the solar sensor's exposure to sunshine is limited. The sensor receives only up to 25% of total possible sunshine exposure this month due to obstruction. There is no allowance for sunshine by visual observation only, so the sunniest day figures above can be very significantly less than the actual daily sunshine duration. THW = Shaded Heat Index calculated with cooling/warming effect of wind and humidity to give an apparent temperature. THSW = Unshaded Heat Index calculated with cooling/warming effect of wind, humidity and full direct sunshine to give an apparent temperature. EVAPO-TRANSPIRATION is drying effect due to sun and wind, and is equivalent to "negative rainfall" |
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DAILY STATS DECEMBER 2011 |
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TEMPERATURE ºc |
HUMIDITY |
SUN ‡ |
PRESSURE |
RAINFALL |
WIND SPEED |
DIRECTION |
WEATHER NOTES ‡ |
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DATE |
Low (21-09h) |
High (09-21h) |
Temp at 14.00z |
RH % at 14.00z |
Dewpoint ºc at 14.00z |
Bright sun hrs |
hPa at 14.00z |
Day Total (mm) |
Average (mph) |
Max Gust (mph) |
Dominant (Compass) |
Precipitation type etc ‡ |
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1st |
9.0 | 12.2 | 9.8 | 88 | 7.9 | 0.1 | 1006.0 | FS | 17.5 | 2.4 | 24 | SW | Rain |
2nd |
3.0 | 7.6 | 6.7 | 84 | 4.2 | 0.3 | 1013.3 | FS | 0.5 | 1.8 | 17 | SW | Rain night pm |
3rd |
5.6 | 11.7 | 11.2 | 62 | 4.2 | 1.7 | 1002.4 | RS | 2.5 | 4.1 | 24 | SW | Rain am |
4th |
7.6 | 9.3 | 9.2 | 77 | 5.3 | 0.0 | 997.8 | F | 0.0 | 2.1 | 14 | SSW | Cloudy |
5th |
2.9 | 6.7 | 6.2 | 68 | 0.7 | 0.2 | 1005.4 | ST | 0.0 | 2.3 | 18 | SSW | Cloudy |
6th |
3.1 | 6.8 | 6.4 | 68 | 0.9 | 0.1 | 1007.1 | ST | 0.0 | 2.8 | 17 | SSW | Cloudy |
7th |
6.0 | 8.9 | 8.5 | 50 | -1.3 | 1.5 | 1007.9 | R | 0.3 | 4.0 | 20 | SW | Sunny periods |
8th |
3.0 | 12.2 | 11.3 | 86 | 9.1 | 0.0 | 1005.7 | FQ | 2.5 | 5.5 | 30 | SW | Rain am, eve |
9th |
4.0 | 7.9 | 7.8 | 59 | 0.3 | 1.8 | 1009.4 | FS | 0.0 | 2.4 | 19 | SSW | Sunny |
10th |
-1.6 | 5.7 | 5.6 | 65 | -0.5 | 1.5 | 1014.3 | FS | 0.0 | 0.5 | 10 | SW | Sunny |
11th |
-1.2 | 8.7 | 7.9 | 78 | 4.3 | 0.0 | 1005.0 | F | 7.1 | 1.5 | 19 | SW | Rain am, eve |
12th |
2.8 | 8.8 | 8.3 | 71 | 3.3 | 1.2 | 1004.9 | FS | 11.2 | 3.7 | 29 | SW | Rain am, night pm |
13th |
6.7 | 11.7 | 7.4 | 59 | -0.1 | 0.8 | 991.5 | RS | 8.9 | 6.2 | 31 | SW | Rain am |
14th |
3.3 | 6.1 | 5.9 | 66 | 0.1 | 0.8 | 994.8 | R | 0.5 | 3.5 | 21 | SW | Rain am |
15th |
4.3 | 7.9 | 7.6 | 69 | 2.3 | 0.8 | 999.2 | RS | 4.1 | 3.8 | 22 | SW | Rain night pm |
16th |
1.6 | 3.9 | 3.6 | 81 | 0.7 | 1.2 | 987.3 | R | 5.8 | 2.6 | 17 | N | Rain/sleet/snow am |
17th |
0.6 | 5.2 | 5.2 | 77 | 1.5 | 1.2 | 1007.1 | FS | 0.0 | 1.5 | 14 | SSW | Sunny spells |
18th |
-0.1 | 5.0 | 4.9 | 75 | 0.8 | 0.2 | 1013.9 | F | 0.0 | 1.1 | 12 | SSW | Cloudy |
19th |
-1.9 | 5.8 | 1.6 | 91 | 0.2 | 0.0 | 1011.8 | F | 4.1 | 0.5 | 11 | SW | Rain pm/eve. |
20th |
5.3 | 7.7 | 7.2 | 70 | 2.1 | 0.1 | 1015.2 | RS | 0.5 | 1.4 | 16 | WNW | Sunny am |
21st |
5.6 | 11.7 | 11.2 | 94 | 10.3 | 0.0 | 1016.3 | RS | 2.5 | 0.6 | 8 | SSW | Rain am |
22nd |
8.6 | 11.9 | 11.8 | 78 | 8.1 | 1.3 | 1023.4 | ST | 0.0 | 1.8 | 13 | WNW | Sunny |
23rd |
9.6 | 10.3 | 10.2 | 89 | 8.5 | 0.0 | 1011.6 | FQ | 4.3 | 5.0 | 21 | SW | Rain |
24th |
3.1 | 7.7 | 7.6 | 73 | 3.0 | 1.5 | 1028.6 | FS | 0.3 | 2.8 | 17 | SW | Sunny spells |
25th |
7.1 | 11.3 | 11.2 | 75 | 6.9 | 0.2 | 1027.2 | ST | 0.0 | 5.3 | 21 | SW | Cloudy |
26th |
10.7 | 11.7 | 11.4 | 85 | 9.0 | 0.0 | 1032.5 | ST | 0.0 | 3.8 | 18 | SW | Overcast |
27th |
9.4 | 10.3 | 10.3 | 72 | 5.5 | 0.0 | 1032.0 | F | 0.0 | 1.5 | 14 | SSW | Overcast |
28th |
7.4 | 11.1 | 9.7 | 73 | 5.1 | 0.5 | 1017.7 | FS | 0.5 | 4.1 | 22 | SW | Light rain |
29th |
4.9 | 9.2 | 7.9 | 82 | 5.1 | 0.0 | 1017.7 | F | 4.8 | 4.5 | 24 | SW | Rain showers |
30th |
4.8 | 7.7 | 7.1 | 75 | 2.9 | 0.0 | 1017.0 | F | 5.3 | 1.3 | 13 | SW | Rain pm/eve |
31st |
5.9 | 12.3 | 12.1 | 85 | 9.7 | 0.0 | 1008.8 | FS | 0.3 | 3.4 | 18 | SW | Rain night pm |
| ‡ SUN: Sunshine hours are calculated approximately and solely from solar radiation readings, but note that the solar sensor's exposure to sunshine is rather limited. The sensor receives less than 25% of total possible sunshine exposure this month, and there is no allowance for sunshine by visual observation only, so the figures above can be very significantly less than the actual daily sunshine duration. |
| Barometer trend (previous 3 hours) : F = falling, ST = steady, R = rising; Q = quickly, S = slowly |
| ‡ Weather Notes use METAR codes: OVC = overcast; SHRA = rain showers; '+' = heavy; CAVOK = no cloud below 5000 ft & visibility> 10 km & no fog, precipitation or snow; SN = snow; RASN = Rain and snow |
| 1st | LP 963 hPa between Faroe and Shetland Isles, HO from Spain to Balkans. Light rain early in the night, rather heavy bursts around rush hour. Some brightness then more rain from mid-afternoon to past midnight. |
| 2nd | Sunny morning, a sheet of cloud crosses during early afternoon. Another band of rain arrives around 23.00. |
| 3rd | Light rain/drizzle early morning, showers around sunrise. Cloud clears to give sunny spells. |
| 4th | A cloudy day, sometimes overcast and sometimes broken cloud with blue sky but no sunshine. A brief light rain shower early evening. |
| 5th | A bright day but extensive medium level cloud allows sunny spells for the morning only. |
| 6th | A cloudy day with a little brightness in the morning. |
| 7th | A little light rain before dawn, a day of sunny periods with a couple of cloudy spells. |
| 8th | LP 957 hPa Outer Hebrides, HP 1032 hPa Spain. Light rain around rush hour, staying cloudy before cold front brings heavier rain during the evening. |
| 9th | Sunny and clear in the morning, some cloud during the afternoon with sunny spells. |
| 10th | Sunny and clear in the morning, some patchy high cloud from midday making the sunshine a little hazy. |
| 11th | Light rain and drizzle for a couple of hours after dawn, a dry but dull spell followed by more drizzle and then rain from 17.30 to 22.00. |
| 12th | A sunny day, clouding over after 15.00, light rain from 16.30 becoming moderate later continuing through the night. |
| 13th | Strong winds and rain overnight, with downpour as cold front passes, clearing around 05.30. Sunny morning, some cloud patches pm. |
| 14th | Some light rain early am, day is a mixture of sunny and cloudy spells. |
| 15th | LP 988 hPa Lincolnshire moving E. A sunny morning, increasing cloud from midday. Rain from just after 21.00 continuing overnight. |
| 16th | LP 973 hPa deepening along the Channel over night into Belgium.
Rain continuing overnight to the early hours. Further rain from 07.00 turns sleety with some snowflakes occasionally to midday. Light covering on North Downs, not settling in town. Sunny spells pm. |
| 17th | Clear morning with ground frost. Sunshine followed by a cloudy period during midday with some brief light rain then sunny spells again. |
| 18th | Clear morning with ground frost. Sunshine followed by a cloudy period after midday. |
| 19th | Quite heavy ground frost, becoming overcast early with drizzle starting around 12.30 and rain persisting. |
| 20th | Light rain shower before dawn. Sunny and clear start, becoming hazy around midday and cloudy soon after. Light rain late night. |
| 21st | Light rain and drizzle on and off into the morning. Staying overcast all day. |
| 22nd | High cloud and haze first thing becoming clearer with unbroken sunshine after 09.30. |
| 23rd | A rather gloomy overcast day with intermittent drizzle from 08:30 followed by heavier rain as cold front passes late pm/evening. |
| 24th | Some lengthy sunny spells athough a little hazy at times. |
25th & |
HP 1042 hPa Central France/Switzerland/Austria. |
| 27th | An overcast and rather dull day. |
| 28th | LP 967 hPa NW of Outer Hebrides. A trace of rain from drizzle as cold front crosses around 08.00 followed by a bright period. Spell of light rain around 13.00h. |
| 29th | Overcast morning, brighter around midday followed by band of rain showers. |
| 30th | Rather cloudy and dull, light rain late pm, heavier rain later for two hours in the evening. |
| 31st | Mainly overcast with just a few brighter but brief glimpses of blue sky. Some light rain after 22.00h. |