Monthly Climate Summary for December 2004 at Hampstead  
                        home daily
                             Dull, dry first half;   changeable but sunny second half   back forward
                       
Overall mean temperature was 5.3 ēC which is +0.3 degC compared with the 1971-2000 average
Mean day maximum (09-21) was 7.5 ēC              
Mean night minimum (21-09) was 3.4 ēC              
Mean 24hr maximum (09-09) was 7.9 ēC which is +0.4 degC compared with the 1971-2000 average
Mean 24hr minimum (09-09) was 2.6 ēC which is +0.1 degC compared with the 1971-2000 average
  Highest day max was 12.5 ēC on  the   23          
  Lowest day max was 2.3 ēC on  the 13          
  Highest night min was 9.3 ēC on  the 23          
  Lowest night min was -3.3 ēC on  the 26          
  Lowest grass min was -16.0 ēC on  the 26          
                       
Total rainfall this month was 47.7 mm which is 72.3 per  cent of the 1971-2000 average  
  Highest daily fall was 13.6 mm on  the 17          
Number of hours with rain was 42.0 hrs              
Equiv. TSR rainfall duration was 29.4 hrs which is 51.6 per  cent of the 1971-2000 average  
  Highest no of wet hrs 7.0 hrs on  the 18          
  Highest equiv duration 5.8 hrs on  the 18          
                       
Total sunshine this month was 52.4 hrs which is 116.5 per  cent of the 1971-2000 average  
Equiv. C/S sunshine total was 57.7 hrs which is 116.5 per  cent of the 1971-2000 average  
  Highest daily sun was 6.4 hrs on  the 26          
                       
Maximum  snow depth  was 0.0 cm              
                       
Mean sea-level pressure at 09Z 1018.8 mbar which is +3.8 mbar compared with the 1961-1990 average
  Highest pressure at 09Z 1032.5 mbar on  the 8          
  Lowest  pressure at 09Z 993.8 mbar on  the 17          
                       
Number of days with:                    
Air Frost 3   0.2mm rain 14   No  sun 8   Snow lying 0  
Grnd Frost 14   1.0mm 5   3h  sun 8   Snow/sleet 0  
Max < 0ēC 0   5mm 4   6h  sun 2   Hail 0  
Max > 10 7   10mm 1   9h  sun 0   Thunder 0  
Max > 20 0   25mm 0   12h sun 0   Fog at 09Z 3  
Max > 30 0         15h sun 0   Gale 0  
                       
Notable events during the month:                 
Rainfall 0.8mm in the first half, 47.0mm in the second half      
Sunshine 10.9 hr in the first half, 41.6 hr in the second half