Average annual temperature is 15.4 °C
Absolute maximum temperature: 40.2 °C
Absolute minimum temperature: 0.4 °C
Number of sunny days: 264 days
Number of rainy days: 101 days
Look at detailed online map of Cornwall
* Weather data for Cornwall United States is based on climate observations for 2026 year
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Absolute maximum temperature (°C) | 17.7 | 17.7 | 19.2 | 30.7 | 30.2 | 36.5 | 40.2 | 38.8 | 33.2 | 35.0 | 25.9 | 17.9 |
| Average daytime temperature (°C) | 13.6 | 13.5 | 14.4 | 20.3 | 22.1 | 25.5 | 33.3 | 33.1 | 28.1 | 26.9 | 19.5 | 15.7 |
| Average temperature (°C) | 9.3 | 8.4 | 9.8 | 14.0 | 15.9 | 18.1 | 22.8 | 23.2 | 20.1 | 18.8 | 13.3 | 10.8 |
| Average night temperature (°C) | 6.1 | 4.3 | 6.7 | 9.3 | 11.8 | 13.2 | 15.3 | 16.5 | 14.9 | 13.1 | 8.4 | 7.2 |
| Absolute minimum temperature (°C) | 0.4 | 0.9 | 2.6 | 4.7 | 8.6 | 11.6 | 12.2 | 13.9 | 11.8 | 5.5 | 1.8 | 2.0 |
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Daylight maximum duration (h) | 10.0 | 11.0 | 12.0 | 13.0 | 14.0 | 14.0 | 14.0 | 14.0 | 13.0 | 11.0 | 10.0 | 9.0 |
| Daylight mean duration (h) | 9.9 | 10.8 | 12.0 | 13.2 | 14.2 | 14.8 | 14.5 | 13.6 | 12.4 | 11.2 | 10.1 | 9.6 |
| Daylight minimum duration (h) | 9.0 | 10.0 | 11.0 | 12.0 | 13.0 | 14.0 | 14.0 | 13.0 | 11.0 | 10.0 | 9.0 | 9.0 |
| Sunshine mean duration (h) | 5.6 | 7.6 | 7.8 | 11.4 | 11.5 | 13.2 | 13.2 | 12.4 | 10.8 | 9.4 | 8.0 | 6.0 |
| Precipitation (mm) | 256 | 83 | 244 | 2 | 31 | 0 | 0 | 2 | 0 | 13 | 81 | 160 |
| Sunny days | 12 | 17 | 11 | 25 | 24 | 29 | 31 | 28 | 27 | 26 | 19 | 15 |
| Rainy days | 19 | 11 | 20 | 5 | 7 | 1 | 0 | 3 | 3 | 5 | 11 | 16 |
| Snow days | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
The best time to visit Cornwall during the most sunny months:
The largest precipitation sum in Cornwall is at