December 2015
A watery December sun shining over Lyme Bay

An exceptionally mild month with average rainfall and below normal sunshine levels.
Summary for  December 2015
Mean Max: 13.5ºC (+4.2ºC)
Mean Min: 9.2ºC (+5.9ºC)
Mean (min+max ÷ 2): 11.3ºC (+5.0ºC)
Mean (integrated):  11.5ºC  
High Max: 15.3ºC 20th
Low Max: 11.2ºC 11th
High Min: 13.7ºC 26th
Low Min: 0.6ºC 9th
Mean Grass Min: 6.8ºC  
Grass Min: -0.6ºC 9th
Days  >15°C 1 Days  
Days >10°C 31 Days  
Nights  >10°C 15 Days  
Nights  <5°C 5 Days  
Rain Total (gauge): 87.7 mm (98%)
Rain Total (tipping bucket): 82.7 mm (92%)
Rain Days >0.2 mm: 26 Days  
Rain Days >1.0 mm: 18 Days  
Max 24 hrs: 15.8 mm 30th
Days without any rain: 5  
Air Frost: 0 Days  
Grass Frost: 1 Day  
Snow Falling: 0 Days  
Snow (50%) @ 9am: 0 Days  
Ice Days: 0 Days  
Thunder Heard: 0 Days  
Hail <5 mm: 0 Days  
Hail >5 mm: 0 Days  
Fog @ 9am: 0 Days  
Total Monthly Sunshine: 58.1 Hours (69%)
Most Sunshine in a Day: 7.5 Hours 29th
Average Daily Sunshine: 1.9 Hours  
Sunless Days: 7 Days  
Cloudless Days: 1 Days  
Total Possible Sunshine: 249.8 Hours  
Percentage of Total Sun: 23%  
Maximum UV Index: 1.1 4th
Time of Max UV: 12:10  
Average Max UV: 0.7  
Mean Soil Temp @ 30 cm: 12.2ºC  
Min Soil Temp @ 30 cm: 11.6ºC 10th
Max Soil Temp @ 30 cm: 13.0ºC 20th
Mean Soil Temp @ 100 cm: 13.5ºC  
Min Soil Temp @ 100 cm: 13.3ºC 1st
Max Soil Temp @ 100 cm: 13.7ºC 21st
Ave 10 Min Wind >39 mph: 0.00 Days  
N: 0.14 Days 0%
NE: 0.06 Days 0%
E: 0.41 Days 1%
SE: 4.52 Days 15%
S: 15.77 Days 51%
SW: 6.04 Days 19%
W: 0.48 Days 2%
NW: 0.45 Days 1%
Calm: 3.13 Days 10%
Wind Chill Low: -1.0ºC 9th
Mean Wind: 8.9 mph  
Max Gust: 50 mph 30th
Mean Cloud Cover: 70%  
Mean RH @ 9am: 92%  
Rain >0.1mm/hour: 27.3 Hours  
Frost Duration: 0.0 Hours  
Air Frost in a Day: 0.0 Hours  
Mean Sea Temperature: 12.2ºC (+2.2ºC)
Normal for Month: 10.0ºC  
Max Sea Temperature: 12.6ºC 7th
Min Sea Temperature: 11.8ºC 31st
Mean Pressure @ 9am: 1017.2 hPa  
Mean Pressure: 1016.8 hPa  
Max Pressure: 1034.2 hPa 9th
Min Pressure: 1001.4 hPa 30th
Max Change in 24 hours: 18.8 hPa 4th
Radiation Daily Mean: 2.15 MJ/m²  
Max Daily Value: 4.90 MJ/m² 8th
Min Daily Value: 0.57 MJ/m² 30th
Number of Days with Data: 31 Days  
1-Hour Maximum: 481 W/m² 4th
Starting Time of the Hour:   12:00
Max Dewpoint: 13.9ºC 27th
Min Dewpoint: -0.4ºC 9th
Mean Dewpoint: 9.7ºC  
Max Humidity: 99% 12th
Min Humidity: 70% 24th
Mean Humidity: 90%  
Weather Data for Otter Valley, Devon. December 2015
  Temp oC Grass Hum (%) Soil oC DP (oC) Wind (mph) Rain Air (hPa) W/m² UV Sun Frost Calm Wind Sea Observations
  Min Max Min Min Max 30 100 Min Max Max Ave Run mm Min Max Max Max Hours Hours Hours Chill Temp
1 12.2 14.1 10.2 72 90 11.9 13.3 8.2 12.0 27 5.8 140 0.0 1019 1025 161 0.8 0.8 0.0 0.0 10.1 12.2 Brief sunny intervals all day
2 11.9 13.7 9.9 79 91 12.2 13.4 8.7 12.0 21 8.9 215 0.2 1021 1024 310 0.8 1.4 0.0 0.0 9.4 12.2 Patchy rain & drizzle all day
3 13.1 14.1 8.2 87 97 12.4 13.5 11.4 13.2 38 12.9 310 2.9 1010 1021 76 0.6 0.0 0.0 0.0 8.7 12.2 Sunny ints & showers all day
4 4.3 14.3 1.3 78 97 12.4 13.5 3.2 12.9 27 5.9 142 0.4 1011 1029 481 1.1 4.9 0.0 3.7 3.1 12.1 Sunny ints am, light rain pm
5 11.3 12.7 9.2 76 84 12.1 13.5 8.0 9.4 35 12.6 303 0.0 1015 1027 70 0.7 0.0 0.0 0.0 7.1 12.3 Sun and showers, windy
6 12.3 14.2 10.5 80 97 12.1 13.6 9.3 12.4 36 10.4 249 0.0 1012 1020 106 0.9 0.0 0.0 0.0 8.9 12.5 Cloudy all day
7 12.3 13.5 10.5 93 98 12.5 13.6 11.2 12.9 22 8.2 197 2.4 1018 1023 248 0.9 3.3 0.0 0.0 9.5 12.6 Sunny intervals all day
8 9.3 13.9 1.8 74 98 12.7 13.6 4.1 13.0 30 8.0 193 4.6 1017 1029 427 0.9 6.3 0.0 1.3 4.7 12.5 Cloudy am, sunny ints pm
9 0.6 12.4 -0.6 78 98 12.1 13.6 -0.4 9.4 23 5.0 121 0.0 1029 1034 369 0.9 4.6 0.0 6.4 -1.0 12.4 Sunny intervals all day
10 9.1 13.0 7.6 72 97 11.6 13.6 6.5 10.7 34 7.9 189 7.0 1021 1030 225 0.8 1.6 0.0 3.7 7.8 12.3 Sunny ints am, rain pm
11 8.8 11.2 4.6 88 97 11.7 13.5 5.6 9.7 15 2.2 53 0.9 1021 1024 170 0.7 1.0 0.0 7.5 6.2 12.3 Brief sunny intervals all day
12 6.4 13.0 8.6 88 99 11.7 13.5 5.8 11.3 27 6.5 155 0.4 1016 1024 102 0.7 0.3 0.0 6.5 6.2 12.2 Cloudy am, sunny ints pm
13 9.1 12.4 6.4 84 96 11.8 13.4 7.9 11.5 19 3.9 95 0.0 1016 1018 78 0.6 1.2 0.0 2.3 8.8 12.2 Rain am, brief sunny ints pm
14 10.6 12.2 8.4 90 97 11.9 13.4 9.3 11.7 24 8.4 202 4.8 1011 1016 76 0.6 0.0 0.0 0.0 8.1 12.1 Cloudy all day
15 10.8 13.5 11.7 95 99 12.0 13.4 10.2 13.3 23 6.9 164 7.3 1011 1014 110 0.7 0.0 0.0 0.3 9.9 12.1 Cloudy all day
16 13.1 14.6 9.8 92 99 12.5 13.4 12.0 13.3 26 8.3 198 0.4 1012 1020 89 0.7 0.9 0.0 0.0 9.8 12.1 Sunny ints am, cloudy pm
17 12.6 14.1 5.6 88 98 12.6 13.5 7.2 13.4 22 5.9 142 3.1 1013 1019 81 0.6 1.0 0.0 2.1 7.6 12.1 Sunny ints am, rain pm
18 8.3 13.3 12.5 95 98 12.6 13.5 10.5 12.7 21 7.1 171 0.2 1015 1019 146 0.9 0.0 0.0 0.3 9.3 12.2 Cloudy all day
19 13.1 14.3 11.8 89 99 12.9 13.6 12.1 13.7 31 12.5 301 9.0 1005 1015 55 0.6 0.0 0.0 0.0 9.7 12.2 Rain am, cloudy pm
20 7.2 15.3 4.1 85 97 13.0 13.6 6.0 13.0 38 8.1 195 1.5 1004 1013 296 0.8 5.2 0.0 3.1 5.8 12.2 Sunny ints and showers
21 6.1 13.9 2.6 88 98 12.4 13.7 5.0 13.3 33 6.1 145 2.4 1011 1018 178 0.7 0.2 0.0 3.4 4.4 12.1 Brief sunny ints all day
22 10.7 13.9 4.7 90 99 12.3 13.7 9.8 13.3 36 11.3 272 2.6 1010 1017 52 0.6 0.0 0.0 0.0 8.8 12.2 Cloudy all day
23 5.4 12.7 2.1 81 95 12.2 13.6 4.0 10.1 26 7.5 180 2.2 1012 1021 410 0.9 6.3 0.0 0.5 3.7 12.1 Brief sunny ints all day
24 4.1 12.2 0.9 70 96 12.0 13.5 2.2 11.2 43 12.0 288 6.4 1005 1019 380 0.9 5.4 0.0 0.6 2.1 12.0 Cloudy am, sunny ints pm
25 3.6 14.6 0.4 85 98 11.6 13.5 2.5 13.3 35 9.8 236 3.7 1016 1020 119 0.0 0.5 0.0 4.5 3.0 11.9 Rain am, sunny intervals pm
26 13.7 15.0 13.1 84 97 11.9 13.5 11.7 13.4 38 16.2 390 1.1 1015 1019 210 0.9 1.3 0.0 0.0 9.9 12.0 Sunny intervals all day
27 12.3 14.9 10.6 90 97 12.5 13.4 11.8 13.9 32 11.5 276 2.2 1015 1021 99 0.7 0.3 0.0 0.0 9.9 12.1 Brief sunny ints all day
28 12.1 13.2 9.9 86 97 12.7 13.5 9.9 11.9 38 10.8 259 0.7 1007 1020 114 0.0 0.4 0.0 0.0 8.5 12.1 Brief sunny ints all day
29 6.4 13.0 3.8 81 95 12.6 13.5 5.1 11.5 37 10.7 268 0.2 1007 1018 332 0.9 7.5 0.0 1.8 5.9 12.0 Brief sunny ints all day
30 9.1 13.7 8.8 88 98 12.4 13.5 7.8 11.9 50 15.7 377 15.8 1001 1014 45 0.0 0.0 0.0 1.7 7.0 11.9 Sunny ints am, cloudy pm
31 4.6 11.6 0.6 76 97 12.3 13.5 1.5 8.6 39 8.9 206 4.8 1003 1018 319 0.9 3.6 0.0 1.5 2.3 11.8 Light rain am, sunny ints pm
9.2 13.5 6.8 84 97 12.2 13.5 7.4 12.1 31 8.9 6632 82.7 1013 1021 191 0.7 58.1 0.0 50 6.9 12.2  
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