Monthly Climate Summary for  October 2009 at Chesham (Tennis Club)
                          home daily
               Often rather cold till the 21st, then warm.  Mostly dry but cloudy.       back forward
                         
Overall mean temperature was 10.6 ēC which is   degC compared with the 1971-2000 average  
Mean day maximum (09-21) was 14.9 ēC which is   degC compared with the 1971-2000 average  
Mean night minimum (21-09) was 6.3 ēC which is   degC compared with the 1971-2000 average  
Mean 24hr maximum (09-09) was 14.9 ēC                
Mean 24hr minimum (09-09) was 6.1 ēC                
  Highest day max was 18.0 ēC on  the   6            
  Lowest day max was 11.2 ēC on  the 17            
  Highest night min was 11.7 ēC on  the 6            
  Lowest night min was -2.1 ēC on  the 18            
  Lowest grass min was   ēC on  the              
                         
Total rainfall this month was 44.7 mm which is   per  cent of the 1971-2000 average    
  Highest daily fall was 8.3 mm on  the 7            
Number of hours with rain was                    
Equiv. TSR rainfall duration was 14.8 hrs which is   per  cent of the 1971-2000 average    
  Highest no of wet hrs   hrs on  the              
  Highest duration 2.8 hrs on  the 7            
  Mean rainfall intensity 3.03 mm/hr                
                         
Total est sunshine this month was 86.8 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 6.4 hrs on  the 2            
                         
Maximum  snow depth  was 0.0 cm on  the               
                         
Mean sea-level pressure at 09Z 1016.4 mbar which is   mbar compared with the 1961-1990 average  
  Highest pressure at 09Z 1033.2 mbar on  the 15            
  Lowest  pressure at 09Z 995.7 mbar on  the 21            
                         
Total number of days with:                      
Air Frost 2   0.2mm rain 16   No  sun 3   Snow lying 2    
Grnd Frost 0   1.0mm 11   3h  sun 11   Snow/sleet 0    
Max < 0ēC 0   5mm 3   6h  sun 4   Hail 0    
Max > 10 31   10mm 0   9h  sun 0   Thunder 0    
Max > 20 0   25mm 0   12h sun 0   Fog at 09Z 0    
Max > 30 0         15h sun 0   Gale 0    
                         
Notable events during the month: