Monthly Climate Summary for  January 2007 at Chesham (Tennis Club)
                          home daily
            Very mild and unsettled until the 20th, then drier and somewhat colder       back forward
                         
Overall mean temperature was 6.9 ēC which is 1.9 degC compared with the 1971-2000 average  
Mean day maximum (09-21) was 9.7 ēC which is 2.4 degC compared with the 1971-2000 average  
Mean night minimum (21-09) was 4.1 ēC which is 1.4 degC compared with the 1971-2000 average  
Mean 24hr maximum (09-09) was 9.7 ēC                
Mean 24hr minimum (09-09) was 3.5 ēC                
  Highest day max was 13.0 ēC on  the   9            
  Lowest day max was 3.4 ēC on  the 23            
  Highest night min was 11.6 ēC on  the 9            
  Lowest night min was -4.7 ēC on  the 26            
  Lowest grass min was   ēC on  the              
                         
Total rainfall this month was 68.8 mm which is 101.6 per  cent of the 1971-2000 average    
  Highest daily fall was 9.4 mm on  the 6            
Number of hours with rain was                    
Estimated rainfall duration* was 25.1 hrs which is   per  cent of the 1971-2000 average    
  Highest no of wet hrs   hrs on  the              
  Highest duration 3.6 hrs on  the 6            
  Mean rainfall intensity 2.74 mm/hr                
                         
Total est sunshine this month was 49.0 hrs which is 101.0 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 6.1 hrs on  the 31            
                         
Maximum  snow depth  was 0.0 cm on  the  28 and 30            
                         
Mean sea-level pressure at 09Z 1016.0 mbar which is +1.4 mbar compared with the 1961-1990 average  
  Highest pressure at 09Z 1032.4 mbar on  the 27            
  Lowest  pressure at 09Z 986.4 mbar on  the 18            
                         
Total number of days with:                      
Air Frost 6   0.2mm rain 21   No  sun 9   Snow lying 0    
Grnd Frost 0   1.0mm 13   3h  sun 7   Snow/sleet 0    
Max < 0ēC 0   5mm 7   6h  sun 1   Hail 0    
Max > 10 15   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:                  
                         
*Rainfall duration is the aggregate of 5-min sampling intervals with 0.2mm or more