July 2009

The River Otter at Tipton St John at the end of a warm, cloudy and humid July day.
The River Otter at Tipton St John at the end of a warm, cloudy and humid July day.
Summary for  July 2009
Mean Max: 20.0ºC (-1.5ºC)
Mean Min: 12.7ºC (+0.4ºC)
Mean: 16.4ºC (-0.5ºC)
     
High Max: 28.0ºC 1st
Low Max: 16.2ºC 29th
High Min: 17.2ºC 2nd
Low Min: 8.7ºC 20th
Mean Grass Min: 9.1ºC  
Grass Min: 5.4ºC 20th
     
Rain Total (gauge): 142.7 mm (351%)
Rain Total (tipping bucket): 142.1 mm (349%)
Rain Days >0.2 mm: 24 Days  
Rain Days >1.0 mm: 19 Days  
Max 24 hrs: 28.3 mm 29th
Days without any rain: 7  
     
Air Frost: 0 Days  
Ground Frost: 0 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: 147h:21m  
Total Monthly Sunshine: 147.2 Hours  
Most Sunshine in a Day: 10h:05m 30th
Average Daily Sunshine: 04h:45m  
Sunless Days: 0 Days  
Cloudless Days: 0 Days  
Total Possible Sunshine: 508h:51m  
Percentage of Total Sun: 29%  
     
Mean Soil Temp @ 30 cm: 13.4ºC  
Min Soil Temp @ 30 cm:    
Max Soil Temp @ 30 cm: 20.2ºC 24th
Mean Soil Temp @ 100 cm: 10.8ºC  
Min Soil Temp @ 100 cm:    
Max Soil Temp @ 100 cm: 17.3ºC 24th
     
Mean 10 Min Wind >39 mph: 0.0 Days  
N: 0.02 Days  
NE: 0.59 Days  
E: 1.74 Days  
SE: 8.92 Days  
S: 5.65 Days  
SW: 5.40 Days  
W: 6.66 Days  
NW: 0.50 Days  
Calm: 1.53 Days  
Mean Wind: 4.3 mph  
Max Gust: 34 mph 17th
     
Mean Cloud Cover: 63%  
Mean RH @ 9am: 81%  
Rain Duration >0.1mm/hour: 67.8 Hours  
Frost Duration: 0.0 Hours  
Max Frost Duration in a Day: 0.0 Hours  
     
Mean Sea Temperature: 16.8ºC  
Normal for Month:    
Max Sea Temperature: 19.2ºC 1st
Min Sea Temperature: 15.6ºC 11th
     
Mean Pressure @ 9am: 1011.9 hPa (-5.3 hPa)
Mean Pressure: 1012.6 hPa (-4.6 hPa)
Max Pressure: 1024.0 hPa 30th
Min Pressure: 1000.6 hPa 22nd
     
Max Dewpoint: 17.5ºC 16th
Min Dewpoint: 6.2ºC 20th
Mean Dewpoint: 11.8ºC  
     
Max Humidity: 98% 21st
Min Humidity: 41% 1st
Mean Humidity: 77% (+1)

 

A dull, very wet month and also it was quite windy at times. Often cool but with a few warmer days as well, especially at the beginning.

The first month since March to break the dry, sunny and warmer than average theme. Colder than July 2008, warmer than July 2007 but duller and much wetter than either.

Exceptionally wet with an anomaly of 350%, this was the highest monthly rainfall anomaly recorded since the station was set up in May 2005 with rain falling on 24 out of the 31 days.
Unusually for July there were no thunderstorms.
Easily the dullest month of this spring/summer period so far with only 147 hours of sunshine. Just 29% of the available sunshine is the lowest recorded for any month since this weather was set up in Spring 2005.
Soil temperatures were generally above normal throughout.
Winds were dominant from the west and south-east directions.
Very high cloud cover and no days of unbroken sunshine.
Sea temperatures were at their highest at the beginning and fell gradually through the rest of the month.
Mean pressure was just -4.6 hPa below normal and indicative of this very unsettled month.
Dewpoints were significantly low through most of the month.
With it being a very wet and cool month, the RH was only just above the long-term average.
Weather Data for Otter Valley, Devon.  July 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 15.7 28.0 21.9 41 87 64 10.0 16.2 13.1 10 1.9 45 0.0 1020 1022 1021 0.0 5.5 Sunny intervals all day
2 17.2 23.2 20.2 52 86 69 10.3 17.2 13.8 14 1.9 46 0.0 1015 1022 1019 0.0 5.5 Sunny ints am, cloudy pm
3 16.0 24.3 20.2 53 90 72 12.3 15.6 14.0 15 2.4 57 4.6 1013 1015 1014 0.0 5.5 Sunny intervals all day
4 13.2 21.4 17.3 64 89 77 10.1 15.5 12.8 20 4.4 105 0.0 1011 1015 1013 10.8 5.5  
5 14.8 21.1 18.0 59 88 74 11.4 13.6 12.5 19 4.1 98 2.8 1008 1011 1009 11.5 5.5  
6 12.9 19.1 16.0 62 88 75 10.4 14.0 12.2 30 5.3 127 5.9 1004 1008 1006 10.8 5.5  
7 13.1 19.3 16.2 69 91 80 11.0 13.8 12.4 27 6.7 160 13.1 1005 1011 1008 12.4 5.5  
8 13.4 19.1 16.3 56 88 72 8.7 11.7 10.2 24 5.3 127 0.2 1011 1017 1014 9.2 5.5  
9 10.2 19.4 14.8 53 88 71 6.7 12.2 9.5 19 3.9 93 0.0 1017 1018 1018 8.2 5.5  
10 11.2 20.8 16.0 53 84 69 6.7 12.7 9.7 15 1.9 45 0.4 1017 1019 1018 8.4 5.5 Sunny ints am, cloudy pm
11 14.3 20.3 17.3 79 92 86 11.6 16.2 13.9 15 3.0 11 8.7 1009 1017 1013 13.9 5.5 Sunny intervals am, rain pm
12 13.3 21.0 17.2 59 92 76 10.9 13.7 12.3 20 4.8 50 8.7 1005 1009 1007 12.3 3.5 Sunny intervals all day
13 10.8 20.4 15.6 69 91 80 8.1 14.0 11.1 25 5.1 122 0.7 1006 1010 1008 7.5 6.9 Sun & light showers all day
14 11.9 19.0 15.5 73 91 82 9.8 14.0 11.9 27 5.4 130 1.5 1005 1008 1007 8.2 1.8 Sunshine & showers all day
15 14.4 21.7 18.1 61 89 75 11.3 14.9 13.1 28 6.6 157 3.5 1004 1017 1011 12.3 6.1 Showers am, sunny ints pm
16 10.9 18.4 14.7 75 90 83 8.3 17.5 12.9 14 2.4 57 13.7 1010 1020 1015 7.8 0.3 Sunny ints am, then rain
17 12.1 17.7 14.9 75 91 83 9.8 12.5 11.2 34 8.5 204 6.5 1004 1013 1008 10.8 2.3 Rain am, brief sunny ints pm
18 12.6 18.9 15.8 63 89 76 10.1 14.3 12.2 16 3.7 88 1.1 1011 1014 1013 10.5 0.7 Sunny ints am, drizzle pm
19 12.3 17.5 14.9 70 88 79 10.1 12.9 11.5 26 4.8 115 6.1 1011 1013 1012 10.1 5.4 Sunshine & showers all day
20 8.7 18.6 13.7 64 91 78 6.2 11.9 9.1 17 2.7 64 0.0 1012 1016 1014 5.4 3.9 Sunny ints am, cloudy pm
21 14.3 17.8 16.1 81 93 87 11.4 15.5 13.5 23 6.2 149 16.8 1002 1013 1007 13.2 1.8 Rain am, drizzle pm
22 13.8 20.4 17.1 62 90 76 10.1 13.3 11.7 24 5.8 139 0.0 1001 1002 1002 11.2 4.1 Cloudy am, sunny ints pm
23 11.2 21.1 16.2 58 91 75 9.2 13.0 11.1 18 2.8 66 1.1 1001 1008 1004 8.0 6.6 Sun & light showers pm
24 12.1 20.4 16.3 60 91 76 9.8 12.8 11.3 24 3.7 88 3.1 1008 1017 1013 8.4 8.5 Sun & showers, fine evening
25 11.4 21.3 16.4 59 91 75 8.7 13.8 11.3 21 3.0 71 0.2 1017 1023 1020 9.2 9.5 Sunny intervals all day
26 13.2 17.1 15.2 76 91 84 10.0 13.7 11.9 21 4.4 106 10.9 1013 1022 1018 10.2 0.3 Cloudy am, rain pm
27 11.6 20.6 16.1 53 92 73 8.8 13.3 11.1 23 3.5 85 4.1 1011 1016 1014 11.7 7.7 Sunny intervals all day
28 11.2 19.6 15.4 67 90 79 8.2 13.3 10.8 22 4.1 97 0.0 1015 1017 1016 8.1 3.5 Sunny intervals all day
29 13.6 16.2 14.9 82 92 87 10.9 14.0 12.5 21 5.6 135 27.0 1009 1015 1012 13.1 0.7 Rain all day, fine evening
30 10.9 19.1 15.0 55 91 73 8.5 12.0 10.3 25 4.7 112 1.3 1013 1024 1018 8.6 10.1 Sunny intervals all day
31 11.9 18.6 15.3 61 87 74 8.6 12.4 10.5 19 3.8 93 0.7 1015 1024 1020 11.2 3.6 Sunny ints am, cloudy pm
12.7 20.0 16.4 63 90 77 9.6 13.9 11.8 21 4.3 3039 142.1 1010 1015 1013 10.1 147.23  

Graphs for July 2009

Figure 1. Temperature and Rainfall for July 2009.
Figure 2. Sunshine, air pressure and mean wind speed for July 2009. Note that sunshine for the first 11 days was averaged over that period as no observations were made and only a total was calculated.
Figure 3. Wind direction for July 2009.
Figure 4. Soil & sea surface temperature (SST) for Lyme Bay for July 2009. Ignore the spikes for the 24th as this was an error in the data.
Figure 5. Wind run, maximum gusts and mean pressure for July 2009.