Monthly Climate Summary for September 2009  at Hampstead
                        home daily
            Prolonged downpour on the 15th, otherwise a quiet, dry, rather warm month   back forward
                       
Overall mean temperature was 15.2 ēC which is +0.8 degC compared with the 1971-2000 average
Mean day maximum (09-21) was 19.2 ēC              
Mean night minimum (21-09) was 11.2 ēC              
Mean 24hr maximum (09-09) was 19.2 ēC which is +0.9 degC compared with the 1971-2000 average
Mean 24hr minimum (09-09) was 11.2 ēC which is +0.8 degC compared with the 1971-2000 average
  Highest day max was 26.6 ēC on  the   8          
  Lowest day max was 15.0 ēC on  the 15          
  Highest night min was 16.2 ēC on  the 8          
  Lowest night min was 8.2 ēC on  the 27          
  Lowest grass min was 2.2 ēC on  the 27          
                       
Total rainfall this month was 66.0 mm which is 100.0 per  cent of the 1971-2000 average  
  Highest daily fall was 53.2 mm on  the 15          
Number of hours with rain was 29.0 hrs              
Equiv. TSR rainfall duration was 20.3 hrs which is 54.9 per  cent of the 1971-2000 average  
  Highest no of wet hrs 13.0 hrs on  the 15          
  Highest equiv duration 10.8 hrs on  the 15          
Mean Rainfall Intensity 3.25 mm/h              
                       
Total sunshine this month was 121.4 hrs which is 93.0 per  cent of the 1971-2000 average  
Equiv. C/S sunshine total was 133.6 hrs which is 93.0 per  cent of the 1971-2000 average  
  Highest daily sun was 8.2 hrs on  the 25          
                       
Maximum  snow depth  was 0.0 cm              
                       
Mean sea-level pressure at 09Z 1023.4 mbar which is +6.7 mbar compared with the 1961-1990 average
  Highest pressure at 09Z 1037.9 mbar on  the 11          
  Lowest  pressure at 09Z 999.9 mbar on  the 3          
                       
Number of days with:                    
Air Frost 0   0.2mm rain 5   No  sun 1   Snow lying 0  
Grnd Frost 0   1.0mm 3   3h  sun 22   Snow/sleet 0  
Max < 0ēC 0   5mm 2   6h  sun 7   Hail 0  
Max > 10 30   10mm 2   9h  sun 0   Thunder 0  
Max > 20 8   25mm 1   12h sun 0   Fog at 09Z 0  
Max > 30 0         15h sun 0   Gale 0  
                       
Notable events during the month: