Average annual temperature is 11.0 °C
Absolute maximum temperature: 28.5 °C
Absolute minimum temperature: -5.9 °C
Number of sunny days: 104 days
Number of rainy days: 261 days
Look at detailed online map of Harwell
* Weather data for Harwell United Kingdom is based on climate observations for 2026 year
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Absolute maximum temperature (°C) | 12.8 | 14.0 | 15.6 | 16.7 | 20.4 | 27.9 | 26.8 | 26.3 | 28.5 | 22.7 | 14.5 | 14.2 |
| Average daytime temperature (°C) | 8.1 | 10.0 | 9.9 | 12.3 | 16.8 | 21.4 | 19.9 | 20.4 | 21.0 | 15.3 | 9.8 | 9.0 |
| Average temperature (°C) | 5.1 | 6.9 | 6.7 | 8.3 | 12.4 | 16.5 | 16.4 | 16.5 | 16.6 | 11.9 | 7.2 | 6.8 |
| Average night temperature (°C) | 2.4 | 4.0 | 3.1 | 4.2 | 7.9 | 11.4 | 12.7 | 12.4 | 12.4 | 8.9 | 4.4 | 4.4 |
| Absolute minimum temperature (°C) | -4.3 | -1.3 | -5.9 | -2.2 | 4.6 | 5.8 | 10.1 | 8.5 | 7.8 | 2.2 | -2.4 | -4.6 |
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Daylight maximum duration (h) | 8.0 | 10.0 | 12.0 | 14.0 | 16.0 | 17.0 | 16.0 | 15.0 | 13.0 | 11.0 | 9.0 | 7.0 |
| Daylight mean duration (h) | 8.2 | 9.8 | 11.9 | 14.0 | 15.9 | 16.9 | 16.4 | 14.7 | 12.7 | 10.6 | 8.7 | 7.6 |
| Daylight minimum duration (h) | 7.0 | 8.0 | 10.0 | 13.0 | 15.0 | 16.0 | 15.0 | 13.0 | 11.0 | 9.0 | 7.0 | 7.0 |
| Sunshine mean duration (h) | 4.1 | 4.7 | 4.8 | 8.2 | 10.3 | 11.4 | 10.3 | 10.4 | 7.9 | 4.3 | 4.2 | 2.1 |
| Precipitation (mm) | 39 | 9 | 90 | 72 | 47 | 71 | 115 | 64 | 110 | 159 | 72 | 107 |
| Sunny days | 11 | 17 | 3 | 9 | 12 | 13 | 4 | 3 | 9 | 8 | 8 | 7 |
| Rainy days | 20 | 11 | 28 | 21 | 19 | 17 | 27 | 28 | 21 | 23 | 22 | 24 |
| Snow days | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
The best time to visit Harwell during the most sunny months:
Months with the longest average daylight duration in Harwell:
The largest precipitation sum in Harwell is at