April 2011

Cowslips in flower on a warm and sunny April day along the south coast of Devon.
Cowslips in flower on a warm and sunny April day along the south coast of Devon.

Summary for  April 2011
Mean Max: 19.4C (+6.7C)
Mean Min: 6.6C (+2.2C)
Mean: 13.0C (+4.5C)
     
High Max: 26.8C 23rd 
Low Max: 11.0C 13th
High Min: 11.4C 1st
Low Min: 0.5C 4th
Mean Grass Min: 4.4C  
Grass Min: -0.9C 4th
     
Rain Total (gauge): 20.1 mm (45%)
Rain Total (tipping bucket): 21.1 mm (47%)
Rain Days >0.2 mm: 4 Days  
Rain Days >1.0 mm: 4 Days  
Max 24 hrs: 7.5 mm 3rd 
Days without any rain: 26  
     
Air Frost: 0 Days  
Ground Frost: 2 Days  
Snow Falling: 0 Days  
Snow (50%) @ 9am: 0 Days  
Thunder Heard: 1 Days  
Hail <5 mm: 0 Days  
Hail >5 mm: 0 Days  
Fog @ 9am: 0 Days  
     
Total Monthly Sunshine: 246h:23m  
Total Monthly Sunshine: 246.4 Hours (128%)
Most Sunshine in a Day: 14.1 28th
Average Daily Sunshine: 08h:12m  
Sunless Days: 1 Days  
Cloudless Days: 12 Days  
Total Possible Sunshine: 414h:39m  
Percentage of Total Sun: 59%  
Maximum UV Index: 6 11th
Average UV Index: 4.6  
     
Mean Soil Temp @ 30 cm: 13.7C  
Min Soil Temp @ 30 cm: 9.4C 1st
Max Soil Temp @ 30 cm: 16.4C 25th
Mean Soil Temp @ 100 cm: 12.0C  
Min Soil Temp @ 100 cm: 8.6C 1st
Max Soil Temp @ 100 cm: 14.7C 30th
     
Mean 10 Min Wind >39 mph: 0.00 Days  
N: 4.54 Days  
NE: 4.55 Days  
E: 3.58 Days  
SE: 4.20 Days  
S: 4.03 Days  
SW: 1.48 Days  
W: 2.33 Days  
NW: 3.62 Days  
Calm: 2.67 Days  
Wind Chill Low: 0.1C 4th
Mean Wind: 3.9 mph  
Max Gust: 35 mph 11th
     
Mean Cloud Cover: 37%  
Mean RH @ 9am: 83%  
Rain Duration >0.1mm/hour: 9.3 Hours  
Frost Duration: 0.0 Hours  
Max Frost Duration in a Day: 0.0 Hours 1st
     
Mean Sea Temperature: 11.6C  
Normal for Month:    
Max Sea Temperature: 14.2C 23rd 
Min Sea Temperature: 9.9C 1st
     
Mean Pressure @ 9am: 1019.8 hPa (+3.6 hPa)
Mean Pressure: 1018.7 hPa (+2.5 hPa)
Max Pressure: 1032.6 hPa 12th
Min Pressure: 1004.3 hPa 2nd 
     
Max Dewpoint: 14.7C 23rd 
Min Dewpoint: -1.6C 13th
Mean Dewpoint: 6.8C  
     
Max Humidity: 92% 3rd 
Min Humidity: 35% 18th
Mean Humidity: 70% (-8)

 

Spring 2011 continues dry and warm with another very warm and very sunny April.

This ended up the warmest April recorded at this station. A maximum temperature of 26.8C on the 23rd was the warmest April day on record. This month continues a trend of ever warmer, drier and sunny Aprils.

Rainfall was well below the average and this April ended up the 2nd driest month on record (2005).
As with April 2007 and 2009, there were no air frosts, and just two slight grass frosts.
Sunshine levels were well above average though this month was not as sunny as April 2010, but more sunny than 2007.
Soil temperatures were above normal at the beginning of the month and continued this way right through.
Winds were dominant from the north and north-easterly directions, demonstrating the 'blocked' nature of this month.
Rainfall duration was only 9.3 hours and cloud amounts were low due to a high number of sunny days.
Sea surface temperatures were above normal at the beginning of the month and continued that way.
Mean pressure was well above the average for April due to persistent anticyclonic conditions.
Dewpoints were rather below average.
The RH ended up being well below normal due to regular incursions of very dry, Continental air.
Weather Data for Otter Valley, Devon.  April 2011  
  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 11.4 12.8 12.1 82 89 86 6.9 9.8 8.4 22 7.0 166 0.0 1012 1018 1015 5.4 0.7 Cloudy am, sunny ints pm
2 10.7 16.2 13.5 60 90 75 5.1 11.1 8.1 22 5.8 140 0.0 1004 1018 1011 2.3 3.4 Sunny intervals all day
3 4.5 16.0 10.3 61 92 77 1.5 10.0 5.8 20 2.8 67 7.5 1013 1016 1014 2.1 3.3 Sunny ints am, showers pm
4 0.5 13.8 7.2 57 92 75 -1.5 7.1 2.8 24 4.4 105 0.0 1017 1022 1019 -0.9 3.4 Sunny intervals all day
5 9.7 14.8 12.3 79 89 84 6.3 10.8 8.6 25 7.2 172 3.3 1018 1023 1021 10.7 0.1 Brief sunny intervals all day
6 7.8 19.7 13.8 51 92 72 5.5 10.5 8.0 16 4.6 110 0.0 1023 1026 1025 1.9 12.8 Sunny all day
7 3.1 23.0 13.1 56 91 74 0.7 14.1 7.4 13 2.6 62 0.0 1025 1030 1027 4.8 11.4 Sunny all day
8 5.7 22.0 13.9 43 92 68 3.6 10.8 7.2 12 2.0 47 0.0 1024 1030 1027 5.3 12.9 Sunny all day
9 6.6 20.3 13.5 52 86 69 3.4 9.5 6.5 27 4.7 113 0.0 1021 1025 1023 8.8 12.2 Sunny all day
10 4.4 23.1 13.8 45 90 68 1.7 11.6 6.7 11 1.7 41 0.0 1021 1024 1022 0.7 12.7 Sunny all day
11 5.6 15.6 10.6 52 90 71 2.3 10.5 6.4 35 6.0 145 0.0 1023 1027 1025 3.2 4.8 Cloudy am, sunny ints pm
12 2.2 14.6 8.4 43 88 66 -1.1 4.4 1.7 19 6.0 144 0.0 1027 1033 1030 -0.8 11.6 Sunny intervals all day
13 2.2 11.0 6.6 64 88 76 -1.6 6.2 2.3 19 3.5 84 3.5 1018 1031 1024 0.2 0.0 Cloudy, rain showers pm
14 8.3 15.8 12.1 67 89 78 5.2 9.5 7.4 15 4.3 104 0.0 1016 1018 1017 8.1 2.5 Cloudy am, sunny ints pm
15 7.0 16.7 11.9 55 90 73 3.6 8.7 6.2 11 1.8 43 0.0 1018 1021 1019 6.1 1.3 Cloudy am, sunny ints pm
16 8.4 15.9 12.2 59 89 74 5.5 8.6 7.1 11 1.6 37 0.0 1021 1023 1022 6.8 2.5 Brief sunny intervals all day
17 2.1 20.7 11.4 36 92 64 -0.5 10.0 4.8 14 2.4 58 0.0 1022 1025 1023 1.0 13.0 Sunny all day
18 5.3 18.8 12.1 35 88 62 1.2 7.8 4.5 25 3.9 95 0.0 1012 1022 1017 2.9 13.1 Sunny all day
19 3.6 25.2 14.4 39 86 63 -0.2 11.7 5.8 11 1.7 40 0.0 1010 1013 1011 1.8 12.8 Sunny all day
20 8.3 25.6 17.0 44 87 66 5.0 13.1 9.1 13 2.4 62 0.0 1011 1014 1013 5.3 12.4 Sunny all day
21 6.5 25.6 16.1 35 87 61 2.9 11.7 7.3 19 2.9 69 0.0 1008 1013 1011 3.3 13.6 Sunny all day
22 9.6 23.5 16.6 42 81 62 4.8 12.2 8.5 14 2.0 49 0.0 1005 1009 1007 6.9 6.2 Sunny intervals all day
23 7.2 26.8 17.0 43 86 65 3.6 14.7 9.2 14 2.6 63 0.0 1008 1014 1011 5.7 12.3 Sunny intervals all day
24 8.6 22.3 15.5 53 89 71 5.8 12.4 9.1 13 4.1 90 0.0 1015 1020 1017 7.1 10.4 Sunny intervals all day
25 10.1 23.1 16.6 42 89 66 6.3 12.4 9.4 16 4.0 95 0.0 1020 1024 1022 7.3 13.0 Sunny all day
26 8.4 20.4 14.4 54 82 68 4.6 10.9 7.8 16 5.2 124 0.0 1023 1025 1024 5.2 11.1 Sunny intervals all day
27 8.2 20.2 14.2 40 82 61 4.2 8.9 6.6 19 5.0 120 0.0 1023 1026 1024 4.9 11.8 Sunny intervals all day
28 3.1 19.7 11.4 40 81 61 -1.0 6.8 2.9 15 4.2 101 0.0 1016 1024 1020 0.4 14.1 Sunny all day
29 9.8 18.2 14.0 62 79 71 5.0 10.7 7.9 19 5.8 140 0.0 1009 1016 1012 6.5 3.3 Sunny intervals all day
30 10.5 19.4 15.0 60 84 72 7.3 14.1 10.7 24 5.7 136 6.8 1005 1009 1007 8.9 3.5 Sunny am, thunderstorm pm
6.6 19.4 13.0 52 88 70 3.2 10.4 6.8 18 3.9 2820 21.1 1016 1021 1019 4.4 246.4  

Graphs for April 2011

Figure 1. Temperature and Rainfall for April 2011.
Figure 2. Sunshine, air pressure and mean wind speed for April 2011.
Figure 3. Wind direction for April 2011.
Figure 4. Soil & sea surface temperature (SST) for Lyme Bay for April 2011.
Figure 5. Wind run, maximum gusts and mean pressure for April 2011.