Climate averages 1991–2020
Hemel Hempstead weather
in August.
A mild, moderately wet month: the 2nd warmest and one of the wettest of the year.
Long-term climate patterns, not a forecast for a particular trip.
August is a mild month in Hemel Hempstead: daytime highs average 20.4°C and nights cool to about 12.8°C. By daytime temperature it is the 2nd warmest of the 12 months.
Expect about 62 mm of rain on roughly 11 days, which makes August a moderately wet month (one of the wettest months of the year). Daylight, from sunrise to sunset, lasts about 14 h 38 min on an average August day.
The nearest other city in this atlas is St Albans (8 km away). In August its highs average 20.7°C, about as warm as Hemel Hempstead, with 62 mm of rain.
Among the 143 cities listed in the United Kingdom, Hemel Hempstead ranks joint 50th of 143 for the warmest August highs and joint 30th of 143 for the driest August (rainfall, lowest first). The mean August high of those 143 cities is 19.7°C; Hemel Hempstead is 0.7°C warmer than that mean.
From August to September, average highs fall by 2.7°C to 17.7°C, and monthly rainfall falls from 62 mm to 51 mm.
The annual picture
August in context
Monthly rainfall
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Hemel Hempstead climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 6.6°C1.9°C | 1.9°C | 54 | 11.2 | 8.48 h |
| February | 7.2°C1.7°C | 1.7°C | 45 | 9.9 | 9.910 h |
| March | 9.6°C2.9°C | 2.9°C | 44 | 10.3 | 11.812 h |
| April | 12.5°C4.6°C | 4.6°C | 50 | 11.4 | 13.814 h |
| May | 15.6°C7.7°C | 7.7°C | 56 | 10.5 | 15.616 h |
| June | 18.5°C10.7°C | 10.7°C | 58 | 10.5 | 16.617 h |
| July | 20.7°C12.9°C | 12.9°C | 58 | 11.2 | 16.216 h |
| August, selected | 20.4°C12.8°C | 12.8°C | 62 | 10.7 | 14.615 h |
| September | 17.7°C10.7°C | 10.7°C | 51 | 9.4 | 12.713 h |
| October | 13.7°C8.0°C | 8.0°C | 60 | 11.3 | 10.711 h |
| November | 9.6°C4.6°C | 4.6°C | 62 | 11.2 | 8.99 h |
| December | 6.9°C2.5°C | 2.5°C | 57 | 11.2 | 7.98 h |
Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
August in nearby cities
- St Albans in AugustUnited Kingdom · 8 kmHigh 20.7°C · Low 13.1°C · 62 mm rain
- Watford in AugustUnited Kingdom · 12 kmHigh 20.8°C · Low 13.3°C · 62 mm rain
- Luton in AugustUnited Kingdom · 14 kmHigh 20.7°C · Low 12.8°C · 61 mm rain
- Harrow in AugustUnited Kingdom · 21 kmHigh 20.8°C · Low 13.3°C · 61 mm rain
- Uxbridge in AugustUnited Kingdom · 23 kmHigh 20.8°C · Low 13.3°C · 60 mm rain
- Stevenage in AugustUnited Kingdom · 24 kmHigh 20.9°C · Low 13.0°C · 62 mm rain
- High Wycombe in AugustUnited Kingdom · 25 kmHigh 20.8°C · Low 13.0°C · 62 mm rain
- Aylesbury in AugustUnited Kingdom · 26 kmHigh 20.7°C · Low 12.8°C · 62 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Hemel Hempstead) is explained once on the Hemel Hempstead year overview and on the Sources, method and limits page.
Watford lies in the same rainfall cell, so its rainfall figures are identical to these; temperatures differ because they come from smaller 0.1° cells.