Monthly Climate Summary for July 2009 at Chesham (Tennis Club)
                          home daily
                            Hot until the 4th, then very unsettled with heavy rain at times       back forward
                         
Overall mean temperature was 16.0 ēC which is   degC compared with the 1971-2000 average  
Mean day maximum (09-21) was 21.0 ēC which is   degC compared with the 1971-2000 average  
Mean night minimum (21-09) was 11.0 ēC which is   degC compared with the 1971-2000 average  
Mean 24hr maximum (09-09) was 21.0 ēC                
Mean 24hr minimum (09-09) was 11.0 ēC                
  Highest day max was 28.7 ēC on  the   1            
  Lowest day max was 17.9 ēC on  the 29            
  Highest night min was 15.3 ēC on  the 1            
  Lowest night min was 6.7 ēC on  the 9            
  Lowest grass min was   ēC on  the              
                         
Total rainfall this month was 93.7 mm which is   per  cent of the 1971-2000 average    
  Highest daily fall was 12.6 mm on  the 17            
Number of hours with rain was                    
Equiv. TSR rainfall duration was 21.3 hrs which is   per  cent of the 1971-2000 average    
  Highest no of wet hrs   hrs on  the              
  Highest duration 3.4 hrs on  the 11            
  Mean rainfall intensity 4.41 mm/hr                
                         
Total est sunshine this month was 128.5 hrs which is   per  cent of the 1971-2000 average    
Equiv. C/S sunshine total was   hrs which is   per  cent of the 1971-2000 average    
  Highest daily sun was 8.1 hrs on  the 1            
                         
Maximum  snow depth  was 0.0 cm on  the               
                         
Mean sea-level pressure at 09Z 1012.1 mbar which is   mbar compared with the 1961-1990 average  
  Highest pressure at 09Z 1023.3 mbar on  the 1            
  Lowest  pressure at 09Z 1002.0 mbar on  the 23            
                         
Total number of days with:                      
Air Frost 0   0.2mm rain 22   No  sun 0   Snow lying 0    
Grnd Frost 0   1.0mm 17   3h  sun 24   Snow/sleet 0    
Max < 0ēC 0   5mm 8   6h  sun 5   Hail 0    
Max > 10 31   10mm 2   9h  sun 0   Thunder 0    
Max > 20 19   25mm 0   12h sun 0   Fog at 09Z 0    
Max > 30 0         15h sun 0   Gale 0    
                         
Notable events during the month: