Average annual temperature is 14.8 °C
Absolute maximum temperature: 36.9 °C
Absolute minimum temperature: -8.9 °C
Number of sunny days: 181 days
Number of rainy days: 184 days
Look at detailed online map of St. Charles
* Weather data for St. Charles 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) | 19.2 | 23.8 | 24.9 | 32.0 | 29.2 | 33.2 | 36.9 | 33.5 | 36.1 | 28.1 | 26.5 | 16.8 |
| Average daytime temperature (°C) | 10.8 | 12.5 | 13.8 | 22.5 | 22.6 | 27.8 | 31.3 | 29.9 | 26.5 | 21.5 | 13.9 | 11.2 |
| Average temperature (°C) | 6.4 | 7.1 | 7.9 | 15.7 | 16.7 | 21.5 | 25.5 | 24.3 | 21.2 | 15.8 | 8.3 | 6.4 |
| Average night temperature (°C) | 3.0 | 2.8 | 2.9 | 10.4 | 11.4 | 16.2 | 21.1 | 20.1 | 16.9 | 11.3 | 4.2 | 2.9 |
| Absolute minimum temperature (°C) | -2.9 | -8.9 | -3.9 | 2.7 | 5.9 | 12.1 | 18.6 | 16.0 | 11.1 | 6.0 | -5.6 | -3.4 |
| 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) | 9.8 | 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) | 5.4 | 6.6 | 7.7 | 9.2 | 10.7 | 10.9 | 11.8 | 10.6 | 8.2 | 8.8 | 7.6 | 5.4 |
| Precipitation (mm) | 82 | 69 | 53 | 125 | 52 | 123 | 133 | 64 | 95 | 47 | 63 | 178 |
| Sunny days | 15 | 16 | 17 | 16 | 15 | 11 | 8 | 9 | 15 | 19 | 23 | 17 |
| Rainy days | 16 | 12 | 14 | 14 | 16 | 19 | 23 | 22 | 15 | 12 | 7 | 14 |
| Snow days | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
The best time to visit St. Charles during the most sunny months:
The largest precipitation sum in St. Charles is at