May 2012


Burgh Island South Devon.

Summary for  May 2012
Mean Max: 18.0C (+2.0C)
Mean Min: 8.3C (+1.0C)
Mean: 13.2C (+1.5C)
     
High Max: 27.5C 25th
Low Max: 10.4C 5th
High Min: 16.1C 26th
Low Min: 1.2C 16th
Mean Grass Min: 7.9C  
Grass Min: -0.2C 16th
     
Rain Total (gauge): 44.1 mm (79%)
Rain Total (tipping bucket): 43.0 mm (76%)
Rain Days >0.2 mm: 9 Days  
Rain Days >1.0 mm: 8 Days  
Max 24 hrs: 8.4 mm 10th
Days without any rain: 22  
     
Air Frost: 0 Days  
Grass Frost: 1 Day  16th
Snow Falling: 0 Days  
Snow (50%) @ 9am: 0 Days  
Thunder Heard: 1 Day  
Hail <5 mm: 0 Days  
Hail >5 mm: 0 Days  
Fog @ 9am: 0 Days  
     
Total Monthly Sunshine: 228.7 Hours (116%)
Most Sunshine in a Day: 14.8 Hours 29th
Average Daily Sunshine: 7.4 Hours  
Sunless Days: 4 Days  
Cloudless Days: 5 Days  
Total Possible Sunshine: 481.8 Hours  
Percentage of Total Sun: 47%  
Maximum UV Index: 8.7 28th
Time of Max UV:   13:30
     
Mean Soil Temp @ 30 cm: -  
Min Soil Temp @ 30 cm: -  
Max Soil Temp @ 30 cm: -  
Mean Soil Temp @ 100 cm: -  
Min Soil Temp @ 100 cm: -  
Max Soil Temp @ 100 cm: -  
     
Mean 10 Min Wind >39 mph: 0.00 Days  
N: 9.69 Days  
NE: 2.09 Days  
E: 3.09 Days  
SE: 1.83 Days  
S: 6.68 Days  
SW: 1.52 Days  
W: 0.35 Days  
NW: 4.93 Days  
Calm: 0.80 Days  
Wind Chill Low: 0.1C 16th
Mean Wind: 3.2 mph  
Max Gust: 26 mph 10th
  31.00 Days  
Mean Cloud Cover: 62%  
Mean RH @ 9am: 87%  
Rain Duration >0.1mm/hour: 34.8 Hours  
Frost Duration: 0.0 Hours  
Max Frost Duration in a Day: 0.0 Hours 1st
     
Mean Sea Temperature: 12.7C (+0.0C)
Normal for Month: 12.7C  
Max Sea Temperature: 16.2C 30th
Min Sea Temperature: 10.4C 1st
     
Mean Pressure @ 9am: 1016.4 hPa (+0.6 hPa)
Mean Pressure: 1016.3 hPa (+0.5 hPa)
Max Pressure: 1039.3 hPa 12th
Min Pressure: 1001.7 hPa 18th
   
Radiation Daily Mean: 20.5 MJ/m  
Max Daily Value: 31.7 MJ/m 26th
Min Daily Value: 4.3 MJ/m 10th
Number of Days with Data: 31 Days  
1-Hour Maximum: 1153 W/m 7th
Starting Time of the Hour:   13:00
     
Max Dewpoint: 20.5C 25th
Min Dewpoint: -0.5C 16th
Mean Dewpoint: 9.2C  
     
Max Humidity: 98% 2nd 
Min Humidity: 39% 12th
Mean Humidity: 78% (+1)

 

A cool, wet start then warmer and increasingly sunny.

This May was a month of contrasts, with a cool and wet spell from the 3rd to the 6th, then average temperatures up until the 20th. From then on it was very warm, sunny and dry.

This was the warmest May since 2008.

Rainfall was below the average, with only 4.8 mm falling from the 11th to the 31st. By the end of the month soil conditions were extremely dry.
As with all previous Mays, there were no air frosts, but there was one grass frost on the 16th with -0.2C.
As can be expected from a warm and dry month, the sunshine levels were a little above average even though there were 4 sunless days.
No soil temperature readings were taken due to relocation of sensors.
The dominant wind direction was northerly with wind from a southerly direction also featuring on a large number of days. This was due to frequent sea breezes and typical for this month.
Rainfall duration was just 39 hours and representative of the dry nature of this month.
Sea surface temperatures gradually increased up until the 20th, then increased more sharply and ending up above average. Though overall, the SST was average due to the cool start.
Mean pressure was slightly above the average for May and indicative of the generally settled nature of this month, especially from the 3rd week onwards.
A new sensor has been added that measures solar irradiance in watts per square metre falling on a horizontal surface.
Dewpoints were often well above the average, and on the 25th the dewpoint reached 20.5C, this is very high for the month of May.
Despite the much higher than average dewpoints, the relative humidity was only slightly above normal.
Weather Data for Otter Valley, Devon.  May 2012  
  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 10.6 15.7 13.2 73 96 85 8.4 11.7 10.1 17 3.2 76 8.2 1011 1019 1015 10.7 10.5 Cloudy early am, then sunny
2 4.6 19.4 12.0 54 98 76 3.7 11.8 7.8 14 2.2 53 0.0 1017 1022 1019 4.9 8.4 Cloudy am, sunny pm
3 9.2 13.3 11.3 81 96 89 8.0 10.1 9.1 10 1.2 29 2.2 1009 1017 1013 9.9 0.0 Cloudy all day
4 7.2 12.8 10.0 74 96 85 6.0 8.8 7.4 10 1.1 26 0.0 1005 1009 1007 7.0 0.0 Cloudy all day
5 6.0 10.4 8.2 65 89 77 3.5 6.5 5.0 17 2.7 66 0.0 1006 1010 1008 7.2 0.0 Cloudy all day
6 6.6 13.5 10.1 60 85 73 3.7 7.4 5.6 18 2.9 69 0.0 1010 1015 1012 7.3 8.4 Sunny intervals all day
7 7.7 16.3 12.0 75 98 87 5.5 12.6 9.1 22 6.1 146 8.4 1009 1015 1012 8.1 3.7 Sunny intervals all day
8 10.9 17.1 14.0 69 97 83 8.6 13.9 11.3 20 5.2 124 4.6 1006 1009 1007 11.5 5.6 Sunny intervals all day
9 9.1 13.6 11.4 75 98 87 8.2 13.0 10.6 20 3.5 84 6.4 1005 1008 1007 10.7 0.2 Brief sunny intervals all day
10 12.7 14.3 13.5 91 98 95 11.8 13.7 12.8 26 7.9 190 8.4 1005 1012 1008 13.2 0.4 Brief sunny intervals all day
11 10.1 15.2 12.7 51 93 72 3.8 11.6 7.7 23 5.6 136 0.0 1012 1031 1022 8.8 9.4 Sunny intervals all day
12 2.5 17.5 10.0 39 97 68 1.4 6.0 3.7 14 2.5 61 0.0 1032 1039 1035 4.3 14.3 Sunny all day
13 2.8 16.6 9.7 54 98 76 1.6 9.1 5.4 23 3.6 87 0.0 1025 1038 1031 5.0 12.2 Sunny intervals all day
14 2.1 13.8 8.0 56 97 77 0.7 11.1 5.9 18 2.6 61 3.2 1015 1025 1020 1.1 3.7 Sunny intervals all day
15 6.1 13.5 9.8 52 90 71 1.6 6.2 3.9 23 5.0 119 0.0 1015 1023 1019 3.3 9.6 Sunny intervals all day
16 1.2 15.7 8.5 58 97 78 -0.5 10.0 4.8 18 3.5 85 0.0 1024 1027 1025 -0.2 9.3 Sunny intervals all day
17 6.9 13.4 10.2 56 95 76 4.7 9.2 7.0 19 2.2 53 0.4 1008 1024 1016 6.8 0.0 Cloudy all day
18 8.9 15.3 12.1 71 85 78 5.3 10.5 7.9 12 1.9 45 0.0 1002 1008 1005 6.3 0.0 Cloudy all day
19 6.2 16.1 11.2 65 98 82 4.8 12.0 8.4 13 1.8 44 0.0 1004 1011 1007 4.6 1.8 Sunny intervals all day
20 9.4 16.9 13.2 66 93 80 7.3 11.2 9.3 15 2.6 68 1.2 1009 1011 1010 9.8 4.4 Sunny intervals all day
21 5.1 21.2 13.2 53 98 76 3.7 12.2 8.0 16 2.7 65 0.0 1009 1014 1011 4.3 10.6 Sunny intervals all day
22 6.8 23.5 15.2 52 96 74 5.6 13.8 9.7 15 3.6 86 0.0 1014 1022 1018 5.8 14.8 Sunny all day
23 10.6 23.9 17.3 59 96 78 9.2 17.5 13.4 15 3.5 84 0.0 1022 1027 1024 9.2 12.0 Misty early am, then sunny
24 11.3 26.2 18.8 69 97 83 9.2 20.3 14.8 13 3.3 72 0.0 1023 1027 1025 9.8 11.3 Misty early am, then sunny
25 15.7 27.5 21.6 45 98 72 10.0 20.5 15.3 16 1.9 46 0.0 1017 1024 1020 13.9 14.6 Sunny all day
26 16.1 25.4 20.8 39 68 54 8.6 12.7 10.7 20 3.2 78 0.0 1015 1018 1016 13.3 14.8 Sunny all day
27 10.9 21.7 16.3 52 93 73 9.1 15.6 12.4 14 2.2 54 0.0 1015 1018 1017 11.1 7.9 Sunny intervals all day
28 7.9 21.1 14.5 68 98 83 6.4 16.3 11.4 17 2.9 70 0.0 1017 1019 1018 6.9 14.2 Sunny intervals all day
29 10.2 22.0 16.1 60 97 79 8.6 16.0 12.3 15 2.5 59 0.0 1016 1019 1018 9.5 14.8 Sunny all day
30 9.4 21.8 15.6 62 98 80 8.4 16.7 12.6 14 2.3 55 0.0 1017 1020 1018 8.9 8.1 Sunny intervals all day
31 11.8 24.0 17.9 52 94 73 10.0 14.6 12.3 15 2.4 56 0.0 1019 1021 1020 10.8 3.6 Sunny intervals all day
8.3 18.0 13.2 61 94 78 6.0 12.3 9.2 17 3.2 2343 43.0 1013 1019 1016 7.9 228.7  

Graphs for May 2012

Figure 1. Temperature and Rainfall for May 2012.
Figure 2. Sunshine, UV Index and solar irradiance for May 2012.
Figure 3. Wind direction for May 2012.
Figure 4. Sea surface temperature & cooling/heating days for May 2012.
Figure 5. Mean wind speed, calm hours and air pressure for May 2012.