Average annual temperature is 13.0 °C
Absolute maximum temperature: 36.2 °C
Absolute minimum temperature: -15.1 °C
Number of sunny days: 215 days
Number of rainy days: 138 days
Number of snow days: 12 days
Look at detailed online map of Grundy County
* Weather data for Grundy 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) | 12.6 | 16.6 | 21.4 | 28.1 | 31.0 | 33.2 | 36.2 | 36.1 | 33.6 | 32.2 | 20.5 | 15.0 |
| Average daytime temperature (°C) | 4.5 | 8.7 | 9.9 | 18.6 | 25.9 | 29.3 | 30.3 | 29.2 | 27.7 | 19.6 | 12.1 | 7.9 |
| Average temperature (°C) | -0.1 | 1.6 | 4.4 | 11.7 | 19.1 | 23.6 | 24.6 | 24.1 | 21.6 | 14.4 | 6.5 | 3.9 |
| Average night temperature (°C) | -3.4 | -3.4 | 0.3 | 6.1 | 13.1 | 17.8 | 19.6 | 19.9 | 16.2 | 10.2 | 2.0 | 0.7 |
| Absolute minimum temperature (°C) | -13.2 | -15.1 | -11.7 | -2.9 | 3.8 | 11.1 | 15.4 | 13.9 | 10.6 | -3.2 | -8.0 | -5.6 |
| 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 | 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 | 15.0 | 14.7 | 13.7 | 12.5 | 11.1 | 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) | 5.6 | 7.7 | 7.0 | 9.8 | 11.2 | 11.9 | 11.3 | 10.9 | 10.5 | 7.6 | 7.1 | 5.1 |
| Precipitation (mm) | 55 | 89 | 84 | 52 | 43 | 52 | 64 | 163 | 10 | 73 | 21 | 76 |
| Sunny days | 19 | 19 | 13 | 19 | 18 | 19 | 15 | 14 | 23 | 17 | 24 | 15 |
| Rainy days | 8 | 7 | 17 | 10 | 13 | 11 | 16 | 17 | 7 | 14 | 4 | 14 |
| Snow days | 4 | 2 | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 2 | 2 |
The best time to visit Grundy County during the most sunny months:
The largest precipitation sum in Grundy County is at