April 2009

Woodland Bluebells here in the Otter Valley at the end of April.
Woodland bluebells here in the Otter Valley at the end of April.
Summary for  April 2009
Mean Max: 15.7C (+3.0C)
Mean Min: 6.0C (+1.6C)
Mean: 10.8C (+2.3C)
     
High Max: 22.2C 20th
Low Max: 11.8C 9th
High Min: 11.1C 30th
Low Min: 0.3C 13th
Mean Grass Min: 2.7C  
Grass Min: -2.8C 13th
     
Rain Total (gauge): 51.4 mm (114%)
Rain Total (tipping bucket): 50.9 mm (113%)
Rain Days >0.2 mm: 14 Days  
Rain Days >1.0 mm: 11 Days  
Max 24 hrs: 11.0 mm 27th
Days without any rain: 16  
     
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: 184h:30m  
Total Monthly Sunshine: 184.5 Hours  
Most Sunshine in a Day: 13h:32m 19th
Average Daily Sunshine: 06h:09m  
Sunless Days: 0 Days  
Cloudless Days: 14 Days  
Total Possible Sunshine: 415h:33m  
Percentage of Total Sun: 44%  
     
Mean Soil Temp @ 30 cm: 11.5C  
Min Soil Temp @ 30 cm: 10.3C 1st
Max Soil Temp @ 30 cm: 13.0C 22nd
Mean Soil Temp @ 100 cm: 10.1C  
Min Soil Temp @ 100 cm: 8.1C 1st
Max Soil Temp @ 100 cm: 10.8C 23rd
     
Mean 10 Min Wind >39 mph: 0.1 Days  
N: 3.32 Days  
NE: 2.31 Days  
E: 4.11 Days  
SE: 9.51 Days  
S: 1.41 Days  
SW: 0.94 Days  
W: 3.39 Days  
NW: 1.61 Days  
Calm: 3.40 Days  
Mean Wind: 4 mph  
Max Gust: 34 mph 8th
     
Mean Cloud Cover: 61%  
Mean RH @ 9am: 85%  
Rain Duration >0.1mm/hour: 36.0 Hours  
Frost Duration: 0.0 Hours  
Max Frost Duration in a Day: 0.0 Hours  
     
Mean Sea Temperature: 10.9C  
Normal for Month:    
Max Sea Temperature: 12.5C 22nd
Min Sea Temperature: 9.3C 3rd
     
Mean Pressure @ 9am: 1013.1 hPa (-3.1 hPa)
Mean Pressure: 1012.3 hPa (-3.9 hPa)
Max Pressure: 1029.0 hPa 22nd
Min Pressure: 994.7 hPa 27th
     
Max Dewpoint: 11.0C 15th
Min Dewpoint: -2.8C 13th
Mean Dewpoint: 5.3C  
     
Max Humidity: 93% 9th
Min Humidity: 36% 11th
Mean Humidity: 73% (-5)

Generally warm and sunny though the month ended slightly cooler with rain.

A lovely month though nowhere near and warm and sunny as the exceptional April of 2007. It was particularly warm from the 10th to the 22nd with the warmest day having a maximum of 22.2C.

Overall an average month with regards to rainfall, though most of the rain fell on just a few days.
There were only 2 grass frosts and no air frosts making this the third 'frostless' April since 2005.
Sunshine levels were well above the average.
Soil temperatures were generally around normal at the beginning of the month but then were above average.
Winds were dominant from the south-east and east.
Rainfall duration for the whole month was only 36 hours.
Sea temperatures gradually rose throughout the month and ended up around normal.
Mean pressure was -3.9 hPa below normal which is surprising given the generally settled nature of this month.
Dewpoints were significantly low at times throughout the whole of the month.
The dry air through the month meant relative humidity ended up being well below normal.

 

Weather Data for Otter Valley, Devon.  April 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 8.4 19.6 14.0 42 79 61 3.1 7.3 5.2 17 2.1 51 0.0 1020 1023 1022 6.5 5.8 Cloudy am, sunny pm
2 5.1 18.3 11.7 53 86 70 1.1 8.7 4.9 14 2.1 50 0.0 1018 1021 1020 0.3 8.8 Mist/low cloud am, sunny pm
3 2.9 15.5 9.2 67 89 78 0.0 8.3 4.2 13 2.0 47 0.0 1015 1019 1017 0.2 6.8 Sunny am, sea fog pm
4 7.4 15.2 11.3 54 91 73 2.2 6.9 4.6 20 5.0 121 4.6 1015 1024 1019 4.3 8.5 Sunny intervals all day
5 1.2 16.6 8.9 47 89 68 -1.3 6.5 2.6 14 1.9 46 0.0 1017 1024 1021 0.0 5.4 No observations made
sunshine duration averaged
from total for this period.
6 7.1 12.8 10.0 70 90 80 3.0 7.3 5.2 21 4.9 117 4.8 1003 1017 1010 0.0 5.4
7 3.4 12.3 7.9 67 91 79 1.3 7.0 4.2 23 4.5 108 1.2 1004 1008 1006 0.0 5.4
8 6.1 16.0 11.1 49 92 71 3.8 8.5 6.2 34 6.7 161 5.8 999 1010 1005 0.0 5.4
9 10.1 11.8 11.0 79 93 86 5.6 9.4 7.5 26 8.2 197 3.1 1002 1010 1006 0.0 5.4
10 9.1 15.1 12.1 66 90 78 4.2 9.5 6.9 21 5.1 122 1.4 1000 1004 1002 0.0 5.4
11 2.3 18.7 10.5 36 89 63 -0.3 4.8 2.3 13 1.5 36 0.0 1005 1012 1008 0.0 5.4
12 0.4 18.4 9.4 46 89 68 -2.5 7.7 2.6 14 1.5 36 0.0 1012 1015 1014 0.0 5.4
13 0.3 14.3 7.3 52 89 71 -2.8 6.4 1.8 20 3.3 79 0.0 1008 1014 1011 -2.8 5.4
14 8.8 14.2 11.5 67 91 79 4.7 8.2 6.5 13 3.2 77 2.6 1006 1008 1007 0.0 5.4
15 8.1 16.9 12.5 70 88 79 4.9 11.0 8.0 18 4.0 96 0.0 1001 1008 1004 0.0 5.4
16 10.3 15.3 12.8 63 86 75 6.1 9.1 7.6 18 5.1 123 0.5 1001 1008 1005 0.0 5.4 Sunny intervals all day
17 5.1 16.9 11.0 63 91 77 2.5 10.1 6.3 10 0.8 19 0.0 1008 1013 1011 1.7 1.8 Sunny ints am, cloudy pm
18 7.4 16.7 12.1 57 87 72 4.4 8.2 6.3 16 2.8 68 0.7 1013 1020 1016 5.8 6.0 Sunny intervals all day
19 4.5 20.8 12.7 49 84 67 1.1 9.3 5.2 13 3.3 78 0.0 1020 1025 1023 0.7 13.5 Sunny all day
20 4.7 21.9 13.3 43 89 66 1.6 9.3 5.5 10 1.1 27 0.0 1025 1028 1026 0.4 7.1 Sunny intervals all day
21 4.2 19.6 11.9 49 88 69 0.9 9.0 5.0 17 3.1 75 0.0 1027 1029 1028 0.2 11.0 Sunny all day
22 6.2 17.7 12.0 61 90 76 3.0 9.9 6.5 13 2.2 54 0.0 1024 1029 1027 1.7 6.0 Sunny intervals all day
23 6.9 16.4 11.7 62 90 76 4.1 8.5 6.3 15 2.6 62 0.0 1018 1024 1021 3.1 8.5 Sunny intervals all day
24 10.6 16.6 13.6 57 82 70 4.3 7.7 6.0 24 6.4 154 0.0 1006 1018 1012 6.1 4.5 Sunny intervals all day
25 6.7 13.6 10.2 58 87 73 3.9 8.4 6.2 34 10.1 242 7.2 1001 1007 1004 5.3 9.0 Sunny intervals all day
26 8.7 14.7 11.7 63 86 75 4.1 7.4 5.8 25 6.9 165 1.2 1005 1007 1006 4.8 2.8 Brief sunny intervals all day
27 7.7 12.6 10.2 63 91 77 3.5 7.1 5.3 24 4.0 96 11.0 995 1005 1000 4.7 4.3 Rain am, showers pm
28 1.1 17.9 9.5 45 90 68 -1.7 6.4 2.4 14 2.1 51 0.0 997 1004 1000 -1.7 10.3 Sunny intervals all day
29 3.0 14.9 9.0 61 89 75 -0.1 8.0 4.0 18 3.7 89 0.7 1004 1011 1007 0.2 4.8 Sunny intervals all day
30 11.1 13.1 12.1 84 91 88 8.2 10.2 9.2 24 6.1 146 6.0 1010 1018 1014 9.6 0.4 Rain, int all day, fine evening
6.0 16.1 11.1 58 89 73 2.5 8.2 5.3 19 3.9 2789 50.9 1009 1015 1012 2.7 184.48  

Graphs for April 2009

Figure 1. Temperature and Rainfall for April 2009.
Figure 2. Wind direction for April 2009.
Figure 3. Soil & sea surface temperature (SST) for Lyme Bay for April 2009.
Figure 4. Wind run, maximum gusts and mean pressure for April 2009.