Average annual temperature is 15.5 °C
Absolute maximum temperature: 40.7 °C
Absolute minimum temperature: -2.2 °C
Number of sunny days: 261 days
Number of rainy days: 104 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) | 17.2 | 16.2 | 18.8 | 30.4 | 32.5 | 37.0 | 40.7 | 39.4 | 33.9 | 32.3 | 23.3 | 17.2 |
| Average daytime temperature (°C) | 12.0 | 12.0 | 13.2 | 20.5 | 24.6 | 28.4 | 36.2 | 34.8 | 28.4 | 24.8 | 17.8 | 14.4 |
| Average temperature (°C) | 7.4 | 6.3 | 8.2 | 13.0 | 17.3 | 20.7 | 27.3 | 26.3 | 20.8 | 17.0 | 11.2 | 9.1 |
| Average night temperature (°C) | 4.0 | 2.1 | 4.5 | 6.9 | 11.2 | 14.1 | 18.8 | 18.8 | 14.6 | 10.6 | 5.9 | 5.0 |
| Absolute minimum temperature (°C) | -2.2 | -0.9 | -1.4 | -0.8 | 6.9 | 9.7 | 11.8 | 14.5 | 11.1 | 3.5 | 0.9 | 0.4 |
| 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 | 14.7 | 14.5 | 13.6 | 12.4 | 11.2 | 10.2 | 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) | 5.5 | 7.3 | 7.2 | 11.7 | 12.1 | 12.9 | 13.5 | 11.9 | 11.2 | 9.8 | 8.4 | 7.0 |
| Precipitation (mm) | 303 | 112 | 295 | 2 | 17 | 1 | 0 | 5 | 35 | 17 | 56 | 112 |
| Sunny days | 12 | 14 | 9 | 27 | 23 | 27 | 31 | 28 | 22 | 27 | 23 | 18 |
| Rainy days | 19 | 14 | 22 | 3 | 8 | 3 | 0 | 3 | 8 | 4 | 7 | 13 |
| Snow days | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
The best time to visit Keystone during the most sunny months:
The largest precipitation sum in Keystone is at