Average annual temperature is 14.5 °C
Absolute maximum temperature: 37.7 °C
Absolute minimum temperature: -11.3 °C
Number of sunny days: 203 days
Number of rainy days: 159 days
Number of snow days: 3 days
Look at detailed online map of Saint Charles County
* Weather data for Saint Charles County 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) | 20.2 | 20.0 | 23.0 | 28.3 | 31.3 | 34.3 | 37.7 | 37.2 | 33.1 | 29.5 | 27.3 | 18.0 |
| Average daytime temperature (°C) | 8.3 | 11.2 | 12.8 | 20.5 | 25.6 | 29.9 | 32.0 | 29.8 | 27.0 | 20.3 | 14.2 | 10.3 |
| Average temperature (°C) | 3.3 | 4.9 | 6.6 | 13.5 | 19.3 | 23.7 | 26.0 | 24.7 | 21.4 | 15.2 | 8.5 | 5.8 |
| Average night temperature (°C) | -0.2 | 0.4 | 2.0 | 7.8 | 13.8 | 17.8 | 21.2 | 20.7 | 16.7 | 11.0 | 3.9 | 2.6 |
| Absolute minimum temperature (°C) | -11.3 | -10.8 | -7.0 | 1.2 | 5.2 | 12.2 | 17.2 | 14.4 | 12.2 | -1.4 | -5.3 | -5.3 |
| 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) | 9.8 | 10.8 | 12.0 | 13.2 | 14.3 | 14.8 | 14.6 | 13.6 | 12.4 | 11.2 | 10.1 | 9.5 |
| 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) | 5.3 | 7.6 | 6.8 | 10.3 | 11.2 | 12.4 | 11.7 | 9.6 | 10.3 | 7.6 | 7.7 | 5.6 |
| Precipitation (mm) | 56 | 60 | 195 | 48 | 99 | 86 | 126 | 241 | 36 | 81 | 22 | 97 |
| Sunny days | 18 | 18 | 14 | 20 | 17 | 18 | 9 | 12 | 19 | 17 | 24 | 17 |
| Rainy days | 11 | 9 | 17 | 10 | 14 | 12 | 22 | 19 | 11 | 14 | 6 | 14 |
| Snow days | 2 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
The best time to visit Saint Charles County during the most sunny months:
The largest precipitation sum in Saint Charles County is at