January 2009
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  January 2009
Mean Max: 7.2ºC (-1.2ºC)
Mean Min: 1.5ºC (-1.2ºC)
Mean: 4.3ºC (-1.1ºC)
     
High Max: 11.6ºC 26th
Low Max: 1.1ºC 7th
High Min: 8.8ºC 12th
Low Min: -8.4ºC 7th
Mean Grass Min: -1.2ºC  
Grass Min: -9.2ºC 7th
     
Rain Total (gauge): 122.4 mm (140%)
Rain Total (tipping bucket): 90.7 mm (104%)
Rain Days >0.2 mm: 16 Days  
Rain Days >1.0 mm: 13 Days  
Max 24 hrs: 16.6 mm 17th
Days without any rain: 15  
     
Air Frost: 10 Days  
Ground Frost: 20 Days  
Snow Falling: 0 Days  
Snow (50%) @ 9am: 0 Days  
Thunder Heard: 0 Days  
Hail <5 mm: 1 Days  
Hail >5 mm: 0 Days  
Fog @ 9am: 0 Days  
     
Total Monthly Sunshine: 77h:54m  
Total Monthly Sunshine: 77.9 Hours  
Most Sunshine in a Day: 07h:43m 6th
Average Daily Sunshine: 02h:30m  
Sunless Days: 6 Days  
Cloudless Days: 1 Days  
Total Possible Sunshine: 265h:11m  
Percentage of Total Sun: 29%  
     
Mean Soil Temp @ 30 cm: 3.7ºC  
Min Soil Temp @ 30 cm: 0.8ºC 8th
Max Soil Temp @ 30 cm: 6.1ºC 17th
Mean Soil Temp @ 100 cm: 5.1ºC  
Min Soil Temp @ 100 cm: 4.0ºC 10th
Max Soil Temp @ 100 cm: 6.0ºC 30th
     
Mean 10 Min Wind >39 mph: 0.1 Days  
N: 1.95 Days  
NE: 4.52 Days  
E: 1.28 Days  
SE: 5.89 Days  
S: 4.72 Days  
SW: 3.41 Days  
W: 4.00 Days  
NW: 1.72 Days  
Calm: 3.52 Days 27.5 Days
Mean Wind: 4.0 mph  
Max Gust: 46 mph 25th
     
Mean Cloud Cover: 59%  
Mean RH @ 9am: 87%  
Rain Duration >0.1mm/hour: 56.3 Hours  
Frost Duration: 101.3 Hours  
Max Frost Duration in a Day: 19.0 Hours 6th
     
Mean Sea Temperature: 7.4ºC  
Normal for Month:    
Max Sea Temperature: 8.1ºC 28th
Min Sea Temperature: 6.4ºC 11th
     
Mean Pressure @ 9am: 1009.7 hPa (-5.6 hPa)
Mean Pressure: 1009.6 hPa (-5.7 hPa)
Max Pressure: 1029.3 hPa 2nd
Min Pressure: 969.8 hPa 23rd
     
Max Dewpoint: 9.0ºC 12th
Min Dewpoint: -11.2ºC 7th
Mean Dewpoint: 1.4ºC  
     
Max Humidity: 93% 16th
Min Humidity: 58% 6th
Mean Humidity: 83% (-3)

 

Very cold, settled and dry until the 10th then much warmer and wet thereafter. No measureable rainfall from the 13th of the previous month until the 11th, a total of 29 consecutive dry days.

A record cold night on the 7th of -8.4°C was over 4°C colder than anything previously recorded since this station was set up in the Spring of 2005. Reasonably sunny, especially during the 1st and 3rd weeks.
All of the rainfall fell after the 11th with the 3rd week being especially wet.
This month was quite frosty and there was rather a high number of grass frosts.
Sunshine levels were around average though there were quite a lot of days without any sunshine whatsoever.
Soil temperatures were generally below normal.
Winds dominated from the south-east and north-east sectors.
There were 10 air frosts which amounted to a total time of over 100 hours with temperatures below 0°C.
Sea temperatures gradually rose from about mid-month onwards.
Mean pressure was -5.7 hPa belownormal.
Dewpoints were significantly low at times during the first and second weeks of the month as dry, cold air fed across from the Continent.
This cold, dry air at the beginning of the month meant relative humidity ended up being below normal.
Weather Data for Otter Valley, Devon.  January 2009  
  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 -0.7 1.7 0.5 83 87 85 -4.0 -1.2 -2.6 18 5.8 140 0.0 1027 1028 1028 -2.8 0.0 Dull all day
2 0.1 5.3 2.7 67 87 77 -3.0 1.2 -0.9 16 3.9 93 0.0 1027 1029 1028 -3.9 4.9 Sunny intervals all day
3 -2.6 2.1 -0.3 67 85 76 -6.6 -1.4 -4.0 17 3.3 80 0.0 1028 1029 1028 -4.5 5.9 Sunny all day
4 -2.4 2.4 0.0 79 84 82 -6.4 -1.3 -3.9 7 0.3 7 0.0 1020 1028 1024 -6.6 0.3 Sunny ints am, cloudy pm
5 -0.9 3.6 1.4 70 89 80 -5.4 0.1 -2.7 22 3.7 88 0.0 1018 1026 1022 -4.2 3.7 Sunny intervals all day
6 -4.6 1.2 -1.7 58 80 69 -8.9 -3.8 -6.4 17 3.4 81 0.0 1025 1028 1027 -7.8 7.7 Sunny all day
7 -8.4 1.1 -3.7 77 86 82 ### -1.7 -6.5 4 0.1 2 0.0 1026 1028 1027 -9.2 0.0 Cloudy all day
8 0.3 4.1 2.2 84 88 86 -3.7 1.6 -1.1 6 0.2 4 0.0 1027 1029 1028 -4.6 0.0 Cloudy all day
9 -1.9 2.3 0.2 77 88 83 -4.2 -0.3 -2.3 12 2.7 64 0.0 1026 1028 1027 -5.8 2.9 Sunny intervals all day
10 -3.1 5.7 1.3 79 90 85 -5.4 2.2 -1.6 12 1.7 40 0.0 1024 1028 1026 -6.3 2.5 Sunny intervals all day
11 1.4 9.6 5.5 78 91 85 -1.2 6.2 2.5 28 6.2 148 0.0 1017 1025 1021 -4.6 1.2 Sunny ints am, cloudy pm
12 8.8 10.8 9.8 80 92 86 5.8 9.0 7.4 27 7.7 184 4.1 1006 1017 1012 4.5 0.0 Rain intermittent all day
13 3.7 8.8 6.3 73 91 82 1.0 6.7 3.9 18 2.2 54 0.7 1008 1012 1010 3.8 4.9 Sunny intervals all day
14 0.1 8.6 4.4 82 92 87 -2.3 6.7 2.2 23 3.0 71 3.1 1010 1014 1012 -3.4 2.1 Sunny am, cloudy pm
15 7.3 8.7 8.0 83 91 87 4.8 6.4 5.6 26 9.5 229 6.2 1008 1010 1009 5.4 0.0 Cloudy am, rain pm
16 8.0 10.4 9.2 77 93 85 5.9 8.4 7.2 22 5.7 137 5.0 1009 1012 1010 4.4 2.4 Sunny intervals all day
17 5.6 9.6 7.6 73 92 83 2.6 7.5 5.1 41 9.0 217 16.6 995 1010 1002 2.5 3.5 Sunny am, cloudy pm
18 2.5 8.2 5.4 68 90 79 0.1 5.9 3.0 34 4.4 107 5.5 992 999 996 -0.8 4.5 Sun & brief showers all day
19 3.1 6.7 4.9 79 91 85 -1.0 4.6 1.8 29 4.5 108 9.6 979 997 988 -1.6 0.7 Sunny ints am after rain
20 0.5 7.1 3.8 64 91 78 -2.8 3.0 0.1 16 1.7 42 1.0 983 996 990 -3.4 5.2 Sunny intervals all day
21 -1.2 8.1 3.5 83 92 88 -3.0 6.3 1.7 32 3.4 83 5.5 993 1003 998 -4.2 2.1 Sunny am, cloudy pm
22 6.4 10.2 8.3 70 93 82 2.0 8.5 5.3 26 6.9 165 8.4 982 992 987 3.7 2.7 Sunny intervals all day
23 4.4 7.5 6.0 65 91 78 -0.9 4.7 1.9 37 7.8 188 10.1 970 987 978 -1.6 6.4 Sunny intervals all day
24 0.3 8.4 4.4 73 91 82 -1.8 5.0 1.6 22 1.3 30 1.4 983 994 988 -1.7 3.4 Sunny ints am, cloudy pm
25 4.5 8.9 6.7 74 91 83 2.3 6.6 4.5 46 6.8 164 13.0 980 989 984 2.4 2.4 Sunny ints and showers
26 1.7 11.6 6.7 84 90 87 -0.1 5.9 2.9 16 1.9 47 0.0 985 1007 996 -0.5 1.9 Sunny intervals all day
27 -0.8 11.6 5.4 87 92 90 -2.0 7.1 2.6 10 0.7 18 0.0 1008 1012 1010 -1.3 1.2 Sunny intervals all day
28 0.3 8.3 4.3 87 93 90 3.2 8.3 5.8 9 0.5 13 0.0 1011 1015 1013 4.4 3.9 Cloudy am, sunny ints pm
29 6.7 11.2 9.0 87 91 89 3.3 5.8 4.6 21 2.2 54 0.0 1011 1015 1013 4.1 0.0 Cloudy all day, drizzle pm
30 1.1 8.7 4.9 81 92 87 2.6 5.4 4.0 22 4.9 117 0.5 1008 1012 1010 4.4 1.2 Rain am, sunny intervals pm
31 5.6 9.8 7.7 79 85 82 1.3 3.0 2.2 36 8.7 193 3.8 1005 1008 1007 2.6 0.4 Brief sunny intervals all day
1.5 7.2 4.5 76 90 83 -1.3 4.1 1.4 22 4.0 2963 90.7 1006 1013 1010 -1.2 77.9  

Graphs for January 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.