Average annual temperature is 10.7 °C
Absolute maximum temperature: 33.0 °C
Absolute minimum temperature: -23.9 °C
Number of sunny days: 147 days
Number of rainy days: 199 days
Number of snow days: 19 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) | 16.7 | 15.0 | 15.4 | 30.3 | 29.3 | 33.0 | 30.9 | 27.3 | 32.4 | 27.9 | 17.7 | 15.0 |
| Average daytime temperature (°C) | 5.7 | 5.6 | 7.6 | 16.5 | 20.4 | 24.0 | 27.5 | 24.7 | 22.0 | 17.3 | 8.4 | 7.3 |
| Average temperature (°C) | 1.8 | 0.6 | 2.5 | 10.4 | 14.0 | 18.2 | 22.6 | 20.1 | 17.6 | 12.7 | 3.6 | 3.0 |
| Average night temperature (°C) | -1.4 | -3.7 | -1.7 | 5.5 | 7.9 | 13.5 | 18.6 | 16.2 | 14.1 | 9.0 | 0.0 | 0.1 |
| Absolute minimum temperature (°C) | -7.8 | -23.9 | -7.6 | -2.4 | 0.4 | 7.2 | 13.0 | 12.0 | 7.3 | 1.5 | -5.6 | -7.6 |
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Daylight maximum duration (h) | 9.0 | 11.0 | 12.0 | 13.0 | 14.0 | 15.0 | 15.0 | 14.0 | 13.0 | 11.0 | 10.0 | 9.0 |
| Daylight mean duration (h) | 9.5 | 10.6 | 11.9 | 13.4 | 14.6 | 15.2 | 14.9 | 13.8 | 12.5 | 11.1 | 9.8 | 9.2 |
| Daylight minimum duration (h) | 9.0 | 10.0 | 11.0 | 12.0 | 14.0 | 15.0 | 14.0 | 13.0 | 11.0 | 10.0 | 9.0 | 9.0 |
| Sunshine mean duration (h) | 4.4 | 6.3 | 7.5 | 8.8 | 12.0 | 10.3 | 11.2 | 10.0 | 7.8 | 7.3 | 7.0 | 4.6 |
| Precipitation (mm) | 128 | 50 | 118 | 95 | 57 | 85 | 247 | 127 | 261 | 132 | 50 | 177 |
| Sunny days | 8 | 13 | 11 | 13 | 21 | 6 | 7 | 8 | 14 | 12 | 19 | 15 |
| Rainy days | 19 | 11 | 15 | 17 | 10 | 24 | 24 | 23 | 16 | 19 | 8 | 13 |
| Snow days | 4 | 4 | 5 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 3 | 3 |
The best time to visit Cornwall during the most sunny months:
The largest precipitation sum in Cornwall is at