Monthly Climate Summary for January 2004 at Hampstead   Home Daily
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                Rather mild and changeable and with frequent rain; sunny second half  
Overall mean temperature was 5.1 ēC which is +0.9 degC compared with the 1971-2000 average
Mean day maximum (09-21) was 7.5 ēC
Mean night minimum (21-09) was 3.1 ēC
Mean 24hr maximum (09-09) was 7.8 ēC which is +1.2 degC compared with the 1971-2000 average
Mean 24hr minimum (09-09) was 2.3 ēC which is +0.6 degC compared with the 1971-2000 average
Highest day max was 12.0 ēC on  the   6
Lowest day max was 2.6 ēC on  the 3
Highest night min was 10.0 ēC on  the 11
Lowest night min was -4.2 ēC on  the 29
Lowest grass min was -10.9 ēC on  the 3
Total rainfall this month was 92.6 mm which is 147.0 per  cent of the 1971-2000 average
Highest daily fall was 10.8 mm on  the 15
Number of hours with rain was 124.0 hrs
Equiv. TSR rainfall duration was 86.8 hrs which is 192.9 per  cent of the 1971-2000 average
Highest no of wet hrs 12.0 hrs on  the 1
Highest equiv duration 9.6 hrs on  the 1
Total sunshine this month was 59.4 hrs which is 140.3 per  cent of the 1971-2000 average
Equiv. C/S sunshine total was 65.3 hrs which is 140.3 per  cent of the 1971-2000 average
Highest daily sun was 7.6 hrs on  the 29
Maximum  snow depth  was 5.0 cm 29
Mean sea-level pressure at 09Z 1008.6 mbar which is -6.3 mbar compared with the 1961-1990 average
Highest pressure at 09Z 1027.3 mbar on  the 18
Lowest  pressure at 09Z 985.4 mbar on  the 13
Number of days with:
Air Frost 10 0.2mm rain 25 No  sun 9 Snow lying 3
Grnd Frost 11 1.0mm 16 3h  sun 8 Snow/sleet 3
Max < 0ēC 0 5mm 9 6h  sun 4 Hail 1
Max > 10 6 10mm 1 9h  sun 0 Thunder 1
Max > 20 0 25mm 0 12h sun 0 Fog at 09Z 0
Max > 30 0 15h sun 0 Gale 1
Notable events during the month:                
A remarkable snow squall, accompanied by thunder and lightning, hit at 1706 gmt on the 28th. 5cm fell in an hour.