May 2010

Bluebells in Gittisham Woods on a warm and sunny May evening.
Bluebells in Gittisham Woods on a warm and sunny May evening.
Summary for  May 2010
Mean Max: 18.1C (+2.1C)
Mean Min: 6.6C (-0.7C)
Mean: 12.3C (+0.7C)
     
High Max: 29.1C 24th
Low Max: 11.1C 9th
High Min: 13.1C 20th
Low Min: 0.1C 12th
Mean Grass Min: 3.8C  
Grass Min: -3.4C 12th
     
Rain Total (gauge): 23.7 mm (42%)
Rain Total (tipping bucket): 23.5 mm (41%)
Rain Days >0.2 mm: 7 Days  
Rain Days >1.0 mm: 6 Days  
Max 24 hrs: 6.1 mm 29th
Days without any rain: 24  
     
Air Frost: 0 Days  
Ground Frost: 5 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: 204h:56m  
Total Monthly Sunshine: 205.0 Hours  
Most Sunshine in a Day: 15h:20m 24th
Average Daily Sunshine: 06h:36m  
Sunless Days: 2 Days  
Cloudless Days: 3 Days  
Total Possible Sunshine: 481h:22m  
Percentage of Total Sun: 43%  
     
Mean Soil Temp @ 30 cm: 10.6C  
Min Soil Temp @ 30 cm: 10.0C 1st
Max Soil Temp @ 30 cm: 12.1C 28th
Mean Soil Temp @ 100 cm: 11.1C  
Min Soil Temp @ 100 cm: 9.2C 14th
Max Soil Temp @ 100 cm: 13.8C 26th
     
Mean 10 Min Wind >39 mph: 0.00 Days  
N: 7.54 Days  
NE: 3.22 Days  
E: 1.49 Days  
SE: 3.93 Days  
S: 2.29 Days  
SW: 1.26 Days  
W: 5.21 Days  
NW: 3.22 Days  
Calm: 2.84 Days  
Mean Wind: 3.3 mph  
Max Gust: 25 mph 30th
     
Mean Cloud Cover: 62%  
Mean RH @ 9am: 72%  
Rain Duration >0.1mm/hour: 15.8 Hours  
Frost Duration: 0.0 Hours  
Max Frost Duration in a Day: 0.0 Hours  
     
Mean Sea Temperature: 12.1C  
Normal for Month:    
Max Sea Temperature: 17.6C 24th
Min Sea Temperature: 10.1C 9th
     
Mean Pressure @ 9am: 1017.6 hPa (+1.8 hPa)
Mean Pressure: 1017.4 hPa (+1.6 hPa)
Max Pressure: 1032.8 hPa 20th
Min Pressure: 1006.4 hPa 29th
     
Max Dewpoint: 15.8C 21st
Min Dewpoint: -3.5C 12th
Mean Dewpoint: 5.8C  
     
Max Humidity: 92% 21st
Min Humidity: 31% 23rd
Mean Humidity: 70% (-7)

 

A dry, generally sunny and warm month.
The first half of the month was dominated by cool nights and reasonably warm days. From mid-month onwards the temperatures climbed both day and night with a notable hot spell from the 20th to the 25th. The temperature peaked at 29.1C on the 24th making it the hottest May day in the record, and the highest temperature since the 25th August 2007.

Slightly cooler than May 2009, mostly due to the prevalence of chilly nights for the first half of the month.

Rainfall was generally light and fell on just a few days through the month.
There were no air frosts though there were quite a few grass frosts.
Sunnier than May 2007, 08 & 09.
Soil temperatures were below normal throughout because of the cold winter, though they recovered somewhat from mid-month onwards.
Winds were dominant from the north and north-west sectors, though towards the end of the month the dominant direction was SSE due to frequent sea breezes.
Rainfall duration was just 15.8 hours.
Sea temperatures rose slowly throughout the month but still remained slightly below normal.
Mean pressure was above normal thanks to the anticyclonic, settled weather that dominated most of this month.
Dewpoints were below normal due to frequent incursions of very dry, Arctic air.
The RH ended up being well below normal.
Weather Data for Otter Valley, Devon.  May 2010  
  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 7.5 15.1 11.3 68 90 79 5.0 9.3 7.2 18 1.3 31 3.8 1008 1010 1009 4.3 0.9 Sunny ints am, showers pm
2 7.1 13.1 10.1 62 90 76 2.6 6.8 4.7 23 5.4 130 2.3 1008 1018 1013 4.7 1.3 Rain am, then sunny ints
3 2.6 13.5 8.1 47 84 66 -0.5 3.5 1.5 21 5.2 125 0.0 1018 1027 1023 -0.5 9.9 Sunny intervals all day
4 2.4 15.9 9.2 44 86 65 -0.7 3.9 1.6 22 5.0 120 0.0 1025 1029 1027 0.6 10.8 Sunny intervals all day
5 3.3 17.9 10.6 45 86 66 0.1 7.6 3.9 16 2.8 68 0.0 1017 1026 1021 0.4 3.5 Sunny intervals all day
6 9.6 14.4 12.0 73 88 81 6.1 10.3 8.2 10 1.5 37 2.3 1011 1017 1014 6.2 1.9 Sun & showers all day
7 6.3 12.8 9.6 57 80 69 0.9 6.2 3.6 18 4.3 102 0.0 1011 1013 1012 3.1 2.9 Brief sunny intervals all day
8 6.5 12.1 9.3 67 81 74 1.6 6.0 3.8 19 5.9 141 0.0 1012 1013 1012 3.1 0.3 Brief sunny intervals all day
9 5.7 11.1 8.4 66 84 75 2.5 4.8 3.7 19 4.8 116 0.0 1011 1014 1012 3.1 1.5 Brief sunny intervals all day
10 4.7 16.7 10.7 41 83 62 1.3 4.5 2.9 21 4.3 103 0.0 1011 1012 1011 3.4 10.6 Sunny am, sunny ints pm
11 6.5 13.1 9.8 46 75 61 0.6 3.5 2.1 14 3.1 74 0.0 1012 1013 1013 5.2 1.0 Sunny intervals all day
12 0.1 15.6 7.9 45 88 67 -3.5 3.5 0.0 15 1.9 45 0.0 1014 1016 1015 -3.4 7.5 Sunny intervals all day
13 0.2 14.5 7.4 56 90 73 -2.5 5.7 1.6 16 2.3 55 0.0 1012 1016 1014 -2.6 7.8 Sunny intervals all day
14 3.9 11.8 7.9 66 88 77 1.1 6.0 3.6 17 3.1 75 0.6 1009 1014 1011 0.8 0.0 Cloudy all day
15 8.1 17.6 12.9 43 89 66 2.1 7.0 4.6 19 3.3 80 0.0 1014 1018 1016 6.3 9.8 Sunny intervals all day
16 2.7 15.7 9.2 67 90 79 -0.5 11.7 5.6 18 2.9 69 2.9 1017 1019 1018 -0.5 2.5 Sunny ints am, showers pm
17 2.3 18.2 10.3 49 91 70 -0.2 9.2 4.5 16 3.2 77 0.0 1020 1027 1023 -0.5 10.8 Sunny intervals all day
18 6.3 20.7 13.5 51 88 70 1.7 10.8 6.3 11 1.9 46 0.0 1027 1029 1028 1.7 8.4 Sunny intervals all day
19 11.1 17.4 14.3 68 83 76 6.9 11.5 9.2 11 2.1 49 0.0 1028 1031 1030 9.3 0.0 Cloudy all day
20 13.1 22.2 17.7 61 89 75 9.3 14.6 12.0 8 0.9 24 0.0 1031 1033 1032 11.7 1.6 Brief sunny intervals all day
21 8.2 28.5 18.4 43 92 68 5.9 15.8 10.9 12 1.5 37 0.0 1029 1032 1030 5.4 9.8 Sunny am, sunny ints pm
22 9.1 25.7 17.4 45 90 68 6.2 14.6 10.4 14 2.4 57 0.0 1026 1030 1028 5.9 15.2 Sunny all day
23 7.1 27.4 17.3 31 90 61 4.0 13.8 8.9 14 2.3 54 0.0 1020 1027 1023 4.1 15.3 Sunny all day
24 6.2 29.1 17.7 31 83 57 1.6 13.2 7.4 13 2.1 45 0.0 1012 1020 1016 3.2 15.3 Sunny all day
25 9.6 25.8 17.7 50 86 68 5.7 15.0 10.4 15 2.3 54 0.0 1009 1013 1011 5.4 12.5 Sunny am, sunny ints pm
26 10.1 20.4 15.3 51 79 65 4.9 10.5 7.7 17 3.3 79 0.0 1008 1010 1009 6.5 8.8 Sunny intervals all day
27 10.7 17.3 14.0 42 87 65 2.4 8.5 5.5 19 4.6 111 5.5 1009 1013 1011 9.3 12.7 Sunny intervals all day
28 4.1 18.2 11.2 47 90 69 0.8 8.7 4.8 16 2.4 58 0.0 1013 1016 1015 1.3 7.0 Sunny am, cloudy pm
29 10.4 17.4 13.9 66 91 79 3.4 13.4 8.4 23 4.9 117 6.1 1006 1016 1011 3.1 1.1 Sunny am, showers pm
30 11.8 18.7 15.3 50 88 69 4.5 10.7 7.6 25 7.6 182 0.0 1009 1018 1013 12.3 5.4 Sunny intervals all day
31 7.6 21.7 14.7 50 85 68 3.8 10.7 7.3 13 2.8 56 0.0 1018 1021 1019 4.7 9.0 Sunny intervals all day
6.6 18.1 12.3 53 87 70 2.5 9.1 6.0 17 3.3 2413 23.5 1015 1020 1017 3.8 205.0  

Graphs for May 2010

Figure 1. Temperature and Rainfall for May 2010.
Figure 2. Sunshine, air pressure and mean wind speed for May 2010.
Figure 3. Wind direction for May 2010.
Figure 4. Soil & sea surface temperature (SST) for Lyme Bay for May 2010.
Figure 5. Wind run, maximum gusts and mean pressure for May 2010.