Average annual temperature is 11.6 °C
Absolute maximum temperature: 33.3 °C
Absolute minimum temperature: -19.0 °C
Number of sunny days: 163 days
Number of rainy days: 192 days
Number of snow days: 10 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) | 17.4 | 16.1 | 16.9 | 31.6 | 30.0 | 33.3 | 32.2 | 30.9 | 32.9 | 27.5 | 19.2 | 15.2 |
| Average daytime temperature (°C) | 7.1 | 7.2 | 9.4 | 18.1 | 21.8 | 25.5 | 29.0 | 26.4 | 23.1 | 18.5 | 10.1 | 8.2 |
| Average temperature (°C) | 3.2 | 1.7 | 3.6 | 11.4 | 14.8 | 19.3 | 23.3 | 21.3 | 18.1 | 13.3 | 4.9 | 3.8 |
| Average night temperature (°C) | -0.1 | -2.7 | -1.1 | 5.9 | 7.9 | 13.9 | 18.4 | 16.8 | 14.1 | 9.0 | 0.8 | 0.5 |
| Absolute minimum temperature (°C) | -4.8 | -19.0 | -7.3 | -2.9 | 2.7 | 8.3 | 12.9 | 11.4 | 6.7 | 1.4 | -5.2 | -6.6 |
| 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 | 15.0 | 15.0 | 14.0 | 13.0 | 11.0 | 10.0 | 9.0 |
| Daylight mean duration (h) | 9.6 | 10.6 | 11.9 | 13.3 | 14.5 | 15.1 | 14.8 | 13.8 | 12.5 | 11.1 | 9.9 | 9.2 |
| 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) | 4.9 | 6.3 | 7.4 | 8.6 | 12.0 | 10.4 | 11.6 | 9.8 | 7.9 | 7.5 | 7.6 | 4.5 |
| Precipitation (mm) | 117 | 53 | 98 | 118 | 37 | 99 | 159 | 115 | 228 | 135 | 70 | 217 |
| Sunny days | 12 | 16 | 9 | 13 | 21 | 9 | 7 | 10 | 14 | 18 | 18 | 16 |
| Rainy days | 18 | 9 | 20 | 17 | 10 | 21 | 24 | 21 | 16 | 13 | 11 | 12 |
| Snow days | 1 | 3 | 2 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 3 |
The best time to visit Cornwall during the most sunny months:
The largest precipitation sum in Cornwall is at