Spring 2009

Cliffs adorned with kidney vetch and sea pnks near Thurlestone, Devon on a warm and sunny day in late April.
Cliffs adorned with kidney vetch and sea pinks near Thurlestone, Devon on a warm and sunny day in late April.
Summary for Spring 2009
Mean Max: 15.6 oC  
Mean Min: 6.0 oC  
Mean: 9.6 oC  
High Max: 25.9 oC 31st May
Low Max: 7.8 oC 4th Mar
High Min: 12.1 oC 28th May
Low Min: -2.2 oC 6th Mar
Mean Grass Min: 3.0 oC  
Grass Min: -4.9 oC 6th Mar
Rain Total (gauge): 141.6 mm  
Rain Total (tipping bucket): 136.4 mm  
Rain Days >0.2: 32 Days  
Rain Days >1.0: 26 Days  
Max 24 hrs: 14.6 mm 28th May
Days without any rain: 60 Days  
Air Frost: 4 Days  
Ground Frost: 16 Days  
Snow Falling: 1 Day 5th Mar 
Snow (50%) @ 9am: 0 Days  
Thunder Heard: 1 Day 15th Apr
Hail <5 mm: 2 Days  
Hail >5 mm: 0 Days  
Fog @ 9am: 1 Days  
Total Monthly Sunshine: 576:12 h:m  
Total Monthly Sunshine: 576.3


Most Sunshine in a Day: 15:4 Hours  
Average Daily Sunshine: 06:15 Hours  
Sunless Days: 3 Days  
Cloudless Days: 13 Days  
Total Possible Sunshine: 1266:4 h:m  
Percentage of Total Sun: 45 %  
Mean Soil Temp @ 30 cm: 10.7 oC  
Min Soil Temp @ 30 cm: 5.0 oC 6th Mar
Max Soil Temp @ 30 cm: 17.0 oC 31st May
Mean Soil Temp @ 100 cm: 9.6 oC  
Min Soil Temp @ 100 cm: 6.2 oC 7th Mar
Max Soil Temp @ 100 cm: 12.8 oC 31st May
Wind >39 mph:


N: 5.77 Days  
NE: 8.83 Days  
E: 8.95 Days  
SE: 16.75 Days  
S: 10.52 Days  
SW: 7.20 Days  
W: 20.43 Days  
NW: 5.51 Days  
Calm: 21.82 Days  
Mean Wind: 4.2 mph  
Max Gust: 48 mph 8th Mar
Mean Cloud Cover: 45 %  
Mean RH @ 9am: 84 %  
Rain Duration >0.1mm/hour: 78.8  Hours  
Frost Duration: 14.5  Hours  
Max Frost Duration in a Day: 9.0  Hours 6th Mar
Mean Sea Temperature: 10.8 oC  
Normal for Month:


Max Sea Temperature: 15.3 oC 31st May
Min Sea Temperature: 7.7 oC 4th Mar
Mean Pressure @ 9am: 1017.8 hPa  
Mean Pressure: 1012.0 hPa  
Max Pressure: 1034.8 hPa 22nd Mar
Min Pressure: 980.2 hPa 5th Mar
Max Dewpoint: 14.4 oC 26th May
Min Dewpoint: -4.9 oC 6th Mar
Mean Dewpoint: 5.2 oC  
Max Humidity: 100 %  
Min Humidity: 36 % 11th Apr
Mean Humidity: 73 %  


A warm, dry and sunny Spring.

A pleasantly warm, sunny and dry Spring with no cold days and only 4 slight air frosts all in March. There were just 3 cloudy days with March and April having strong positive sunshine anomalies. Only 3 days failed reach at least 10C and these were at the beginning of March. Warmer than 2008, slightly cooler than 2007 but much drier and sunnier than either.

Whilst there were rainy spells, these were generally short-lived and not heavy in nature shown by the most rainfall in 24 hours to be just 14.6 mm on the 28th of May.
This spring had four frosty nights, all at the beginning of March meaning April & May were completely frost-free.
Sunshine levels were well above average for March and April and around average for May.
Soil temperatures were generally around normal at the beginning of March but were above average at the end of May.
Wind directions were generally variable and not really dominated to any great extent from any particular direction.
Total rain duration was just 78.8 hours for the 3 months of Spring.
As expected, sea temperatures gradually rose throughout the Spring and ended up slightly above normal.
Overall mean pressure was around normal.
Dewpoints were significantly low at times due to the dominance of dry air.
This dry air during many settled spells of this Spring meant that average relative humidity ended up being below normal.

Graphs for Spring 2009

Figure 1. Temperature and Rainfall for Spring 2009.
Figure 2. Sunshine, air pressure and mean wind speed for Spring 2009. Note that for the 5th to the 16th of April no readings were taken and the total sunshine for that period was averaged across those dates.
Figure 3. Wind direction for Spring 2009.
Figure 4. Soil & sea surface temperature (SST) for Lyme Bay for Spring 2009.