December 2008
A robin in my garden all fluffed up against the cold.
A robin in my garden all fluffed up against the cold of a December day.
Summary for   December 2008
Mean Max: 7.4ºC (-1.7ºC)
Mean Min: 1.7ºC (-1.8ºC)
Mean: 4.6ºC (-1.7ºC)
     
High Max: 12.3ºC 20th
Low Max: 0.4ºC 31st
High Min: 10.3ºC 20th
Low Min: -4.1ºC 31st
Mean Grass Min: -0.7ºC  
Grass Min: -5.8ºC 7th
     
Rain Total (gauge): 79.3 mm (82%)
Rain Total (tipping bucket): 77.1 mm (79%)
Rain Days >0.2 mm: 8 Days  
Rain Days >1.0 mm: 7 Days  
Max 24 hrs: 43.2 mm 13th
Days without any rain: 23  
     
Air Frost: 9 Days  
Ground Frost: 21 Days  
Snow Falling: 0 Days  
Snow (50%) @ 9am: 0 Days  
Thunder Heard: 0 Days  
Hail <5 mm: 0 Days  
Hail >5 mm: 0 Days  
Fog @ 9am: 0 Days  
     
Total Monthly Sunshine: 112h:41m  
Total Monthly Sunshine: 112.7 Hours  
Most Sunshine in a Day: 07h:35m 26th
Average Daily Sunshine: 03h:38m  
Sunless Days: 3 Days  
Cloudless Days: 8 Days  
Total Possible Sunshine: 249h:16m  
Percentage of Total Sun: 45%  
     
Mean Soil Temp @ 30 cm: 4.4ºC  
Min Soil Temp @ 30 cm: 1.7ºC 31st
Max Soil Temp @ 30 cm: 7.6ºC 22nd
Mean Soil Temp @ 100 cm: 6.5ºC  
Min Soil Temp @ 100 cm: 5.7ºC 13th
Max Soil Temp @ 100 cm: 7.8ºC 1st
     
Mean 10 Min Wind >39 mph: 0.1 Days  
N: 3.31 Days  
NE: 7.03 Days  
E: 1.47 Days  
SE: 1.71 Days  
S: 1.61 Days  
SW: 3.43 Days  
W: 5.02 Days  
NW: 3.81 Days  
Calm: 8.44 Days  
Mean Wind: 3 mph  
Max Gust: 40 mph 13th
     
Mean Cloud Cover: 64%  
Mean RH @ 9am: 87%  
Rain Duration >0.1mm/hour: 32.5 Hours  
Frost Duration: 93.0 Hours  
Max Frost Duration in a Day: 22.0 Hours 11th
     
Mean Sea Temperature: 9.0ºC  
Normal for Month:    
Max Sea Temperature: 10.0ºC 1st
Min Sea Temperature: 7.9ºC 31st
     
Mean Pressure @ 9am: 1017.3 hPa (+1.3 hPa)
Mean Pressure: 1018.1 hPa (+2.1 hPa)
Max Pressure: 1036.2 hPa 23rd
Min Pressure: 979.8 hPa 5th
     
Max Dewpoint: 9.1ºC 20th
Min Dewpoint: -7.5ºC 31st
Mean Dewpoint: 1.6ºC  
     
Max Humidity: 93% 16th
Min Humidity: 58% 1st
Mean Humidity: 83% (-4)

A very sunny and cold month; wet up to the 13th then dry with no measureable rainfall from the 14th - 31st giving 18 consecutive dry days and is the equal longest dry spell of the year (Feb 8th - 25th). Heavy rainfall on the 13th when 43 mm fell between 00:00 and 08:00 causing widespread flooding and damage for the 2nd time this year.

Apart from a warm spell from the 12th - 24th, days were generally cold with plenty of air frosts at night. The month ended very cold with a day maximum of just 0.4°C on the 31st, this was the lowest maximum temperature recorded since this station was set up in Spring 2005.

The majority of the rainfall fell during the first 13 days with a very night on the 13th leading flooding. Overall the month was a little drier than normal.
This month was quite frosty and there was rather a high number of grass frosts. The 31st was the joint coldest night recorded in the last 3 years.
Sunshine levels were above normal with 8 cloudless days.
Soil temperatures were generally below normal.
Winds dominated from the west and north-east sectors.
There were 9 air frosts which amounted to a total time of 93 hours with temperatures below 0°C.
Sea temperatures fell gradually throughout the month and on the whole were around average or slightly below average, especially at the end of the month.
Mean pressure was 2.1 hPa above normal.
Dewpoints were significantly low at times during the final week of the month as dry, cold air fed across from the Continent.
This cold, dry air at the end to the month meant relative humidity ended up being below normal.
 
Weather Data for Otter Valley, Devon.  December 2008  
  Temp (oC) Hum (RH%) Dewpoint (oC) Wind (mph) Rain Pressure (hPa) Grass Sun  
  Min Max Ave Min Max Ave Min Max Ave Max Ave Run mm Min Max Ave Min Hours Observations
1 -3.1 5.8 1.4 58 90 74 -5.8 1.2 -2.3 14 2.2 53 0.0 1000 1011 1006 -3.5 7.4 Sunny all day
2 -2.8 5.7 1.5 84 91 88 -5.5 3.9 -0.8 13 1.1 27 11.2 1000 1012 1006 -4.4 1.7 Sunny intervals am, rain pm
3 1.1 5.2 3.2 70 90 80 -2.9 2.6 -0.2 11 2.0 48 1.3 996 1005 1000 -1.8 7.4 Sunny all day
4 5.1 9.2 7.2 76 92 84 -2.0 7.1 2.6 27 6.0 144 10.1 981 1003 992 -1.8 2.8 Sunshine & showers all day
5 3.7 8.7 6.2 73 90 82 1.4 5.1 3.3 25 6.2 149 7.2 980 999 989 0.8 5.2 Sunshine & showers all day
6 0.1 8.6 4.4 68 91 80 -2.3 5.9 1.8 24 2.4 59 0.0 999 1021 1010 -1.3 7.5 Sunny all day
7 -2.4 8.4 3.0 73 92 83 -4.4 6.7 1.2 8 0.5 12 0.0 1022 1028 1025 -5.5 7.5 Sunny all day
8 -1.8 8.1 3.2 81 91 86 -3.8 5.3 0.8 5 0.2 4 1.2 1016 1028 1022 -4.4 2.3 Sunny intervals all day
9 0.7 7.3 4.0 78 90 84 -1.5 4.0 1.3 24 4.8 114 1.9 1017 1023 1020 -2.7 2.9 Sunshine & showers all day
10 -2.7 6.2 1.8 78 91 85 -5.0 4.4 -0.3 9 1.0 24 0.0 1016 1024 1020 -4.8 3.6 Sunny ints, showers pm
11 -3.9 2.2 -0.9 87 91 89 -6.0 1.8 -2.1 4 0.0 1 0.0 1011 1016 1014 -5.1 3.7 Sunny am, cloudy pm
12 0.3 9.5 4.9 77 92 85 -3.5 7.2 1.9 34 3.1 74 1.0 1000 1014 1007 -4.3 2.0 Sunny ints am, cloudy pm
13 3.8 10.1 7.0 91 92 92 -0.1 8.2 4.1 40 5.0 121 43.2 987 1000 993 1.7 0.6 Brief sunny ints pm
14 0.2 5.8 3.0 90 92 91 -1.7 4.1 1.2 14 1.2 28 0.0 989 1009 999 -1.9 6.0 Sunny intervals all day
15 -0.2 7.9 3.9 80 91 86 -2.4 5.1 1.4 18 3.1 75 0.0 1009 1020 1014 -2.3 5.6 Sunny intervals all day
16 -2.4 8.9 3.3 87 93 90 -4.1 7.4 1.7 13 0.8 20 0.0 1010 1020 1015 -4.4 0.4 Brief sunny ints am, dull pm
17 0.4 9.1 4.8 76 93 85 -1.5 7.6 3.1 20 1.6 38 0.0 1010 1019 1015 -2.3 6.3 Sunny intervals all day
18 4.2 11.5 7.9 74 92 83 1.9 8.2 5.1 17 3.5 85 0.0 1018 1020 1019 0.2 0.4 Brief sunny intervals all day
19 0.8 10.6 5.7 78 91 85 -1.3 7.7 3.2 21 2.5 60 0.0 1020 1028 1024 -1.7 0.7 Brief sunny intervals all day
20 10.3 12.3 11.3 82 88 85 5.9 9.1 7.5 25 6.9 166 0.0 1023 1031 1027 6.4 0.8 Brief sunny intervals all day
21 9.5 11.2 10.4 76 84 80 5.9 7.3 6.6 24 5.4 129 0.0 1032 1034 1033 7.6 0.3 Brief sunny intervals all day
22 9.1 10.2 9.7 83 91 87 6.1 7.7 6.9 11 2.1 52 0.0 1034 1036 1035 7.5 2.1 Sunny intervals all day
23 8.4 9.3 8.9 85 91 88 5.9 7.0 6.5 11 2.2 52 0.0 1034 1036 1035 7.0 0.0 Dull all day
24 8.1 9.2 8.7 76 87 82 3.7 5.9 4.8 7 1.3 31 0.0 1033 1036 1034 6.2 0.0 Dull all day
25 5.5 7.5 6.5 74 86 80 1.3 3.7 2.5 16 3.4 82 0.0 1032 1034 1033 5.3 2.8 Cloudy am, sunny pm
26 3.1 5.7 4.4 60 80 70 -2.9 1.3 -0.8 23 5.8 138 0.0 1033 1035 1034 1.1 7.6 Sunny all day
27 0.3 4.1 2.2 65 82 74 -3.4 -0.7 -2.1 25 7.1 170 0.0 1030 1035 1033 -2.6 7.3 Sunny all day
28 0.1 4.1 2.1 68 84 76 -3.6 0.0 -1.8 30 8.3 200 0.0 1025 1030 1027 -2.6 7.1 Sunny all day
29 0.3 2.2 1.3 77 84 81 -3.5 -1.5 -2.5 21 5.2 126 0.0 1025 1027 1026 -2.8 0.0 Cloudy all day
30 0.4 5.5 3.0 71 85 78 -3.7 1.9 -0.9 16 3.8 92 0.0 1027 1029 1028 -0.6 7.0 Sunny all  day
31 -4.1 0.4 -1.9 80 89 85 -7.5 -2.1 -4.8 15 1.9 47 0.0 1026 1028 1027 -5.8 3.9 Sunny intervals all day
1.7 7.4 4.6 77 89 83 -1.5 4.8 1.6 18 3.2 2416 77.1 1014 1022 1018 -0.7 112.7  

Graphs for December 2008
Figure 1. Temperature and Rainfall for December 2008.
Figure 2. Sunshine, air pressure and mean wind speed for December 2008.
Figure 3. Wind direction for December 2008.
Figure 4. Soil & sea surface temperature (SST) for Lyme Bay for December 2008.
Figure 5. Wind run, maximum gusts and mean pressure for December 2008.