| Monthly Climate Summary for June 2009 at Hampstead | ||||||||||||||
| home | daily | |||||||||||||
| Alternating warm and cool spells; several heavy thundery downpours | back | forward | ||||||||||||
| Overall mean temperature was | 16.0 | ēC | which is | +0.9 | degC | compared with the 1971-2000 average | ||||||||
| Mean day maximum (09-21) was | 20.8 | ēC | ||||||||||||
| Mean night minimum (21-09) was | 11.2 | ēC | ||||||||||||
| Mean 24hr maximum (09-09) was | 20.8 | 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 | 28.4 | ēC | on the | 29 | ||||||||||
| Lowest day max was | 12.3 | ēC | on the | 5 | ||||||||||
| Highest night min was | 16.4 | ēC | on the | 29 | ||||||||||
| Lowest night min was | 5.9 | ēC | on the | 4 | ||||||||||
| Lowest grass min was | -0.2 | ēC | on the | 4 | ||||||||||
| Total rainfall this month was | 111.8 | mm | which is | 189.4 | per cent | of the 1971-2000 average | ||||||||
| Highest daily fall was | 33.2 | mm | on the | 27 | ||||||||||
| Number of hours with rain was | 51.0 | hrs | ||||||||||||
| Equiv. TSR rainfall duration was | 35.7 | hrs | which is | 108.2 | per cent | of the 1971-2000 average | ||||||||
| Highest no of wet hrs | 11.0 | hrs | on the | 5 | ||||||||||
| Highest equiv duration | 9.1 | hrs | on the | 5 | ||||||||||
| Mean Rainfall Intensity | 3.13 | mm/h | ||||||||||||
| Total sunshine this month was | 179.5 | hrs | which is | 99.2 | per cent | of the 1971-2000 average | ||||||||
| Equiv. C/S sunshine total was | 197.4 | hrs | which is | 99.2 | per cent | of the 1971-2000 average | ||||||||
| Highest daily sun was | 12.2 | hrs | on the | 2 | ||||||||||
| Maximum snow depth was | 0.0 | cm | ||||||||||||
| Mean sea-level pressure at 09Z | 1018.9 | mbar | which is | +2.0 | mbar | compared with the 1961-1990 average | ||||||||
| Highest pressure at 09Z | 1030.3 | mbar | on the | 23 | ||||||||||
| Lowest pressure at 09Z | 1001.4 | mbar | on the | 7 | ||||||||||
| Number of days with: | ||||||||||||||
| Air Frost | 0 | 0.2mm rain | 11 | No sun | 1 | Snow lying | 0 | |||||||
| Grnd Frost | 1 | 1.0mm | 7 | 3h sun | 24 | Snow/sleet | 0 | |||||||
| Max < 0ēC | 0 | 5mm | 5 | 6h sun | 15 | Hail | 0 | |||||||
| Max > 10 | 30 | 10mm | 4 | 9h sun | 7 | Thunder | 2 | |||||||
| Max > 20 | 17 | 25mm | 2 | 12h sun | 1 | Fog at 09Z | 0 | |||||||
| Max > 30 | 0 | 15h sun | 0 | Gale | 0 | |||||||||
| Notable events during the month: | ||||||||||||||
| Severe thunderstorm on the 27th; 22.7mm fell in 30min (1650-1720z), and 29.7mm in 65min (1625-1730z) | ||||||||||||||