Average annual temperature is 12.8 °C
Absolute maximum temperature: 32.5 °C
Absolute minimum temperature: -10.8 °C
Number of sunny days: 149 days
Number of rainy days: 206 days
Number of snow days: 10 days
Look at detailed online map of Keystone
* Weather data for Keystone 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) | 18.8 | 21.7 | 22.7 | 29.1 | 28.8 | 32.5 | 32.3 | 31.6 | 31.4 | 27.2 | 20.3 | 18.2 |
| Average daytime temperature (°C) | 9.4 | 12.3 | 12.3 | 19.8 | 22.2 | 26.1 | 28.8 | 27.2 | 24.1 | 18.8 | 12.6 | 9.9 |
| Average temperature (°C) | 4.4 | 5.7 | 5.9 | 12.6 | 15.7 | 19.7 | 23.1 | 21.7 | 18.7 | 13.5 | 6.6 | 5.1 |
| Average night temperature (°C) | 1.1 | 0.9 | 1.1 | 6.6 | 9.8 | 13.9 | 18.6 | 17.2 | 14.3 | 9.5 | 2.2 | 1.7 |
| Absolute minimum temperature (°C) | -5.6 | -10.8 | -8.2 | -0.3 | 2.6 | 9.6 | 15.5 | 11.3 | 8.5 | 1.2 | -6.9 | -5.2 |
| 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) | 9.7 | 10.7 | 12.0 | 13.3 | 14.4 | 14.9 | 14.6 | 13.7 | 12.5 | 11.2 | 10.0 | 9.4 |
| 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) | 3.2 | 6.7 | 6.7 | 8.4 | 9.9 | 11.1 | 11.1 | 10.5 | 8.9 | 6.7 | 6.9 | 4.9 |
| Precipitation (mm) | 97 | 90 | 95 | 41 | 77 | 101 | 132 | 174 | 79 | 82 | 48 | 76 |
| Sunny days | 7 | 13 | 12 | 14 | 18 | 11 | 6 | 10 | 12 | 13 | 19 | 14 |
| Rainy days | 21 | 12 | 17 | 16 | 13 | 19 | 25 | 21 | 18 | 18 | 10 | 16 |
| Snow days | 3 | 3 | 2 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 1 |
The best time to visit Keystone during the most sunny months:
The largest precipitation sum in Keystone is at