Average annual temperature is 6.1 °C
Absolute maximum temperature: 33.5 °C
Absolute minimum temperature: -28.4 °C
Number of sunny days: 216 days
Number of rainy days: 101 days
Number of snow days: 48 days
Look at detailed online map of McLean County
* Weather data for McLean 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) | 2.0 | 3.7 | 0.3 | 13.9 | 27.1 | 30.3 | 32.7 | 33.5 | 32.5 | 27.3 | 11.2 | 10.4 |
| Average daytime temperature (°C) | -5.6 | -3.8 | -5.5 | 6.0 | 20.9 | 25.5 | 26.5 | 27.0 | 23.0 | 11.4 | 4.5 | 2.1 |
| Average temperature (°C) | -9.2 | -8.7 | -9.7 | 0.8 | 14.3 | 20.3 | 20.5 | 21.2 | 17.5 | 7.0 | 0.4 | -2.0 |
| Average night temperature (°C) | -12.1 | -12.7 | -13.1 | -3.1 | 8.3 | 15.1 | 15.7 | 16.7 | 13.1 | 3.8 | -2.9 | -4.9 |
| Absolute minimum temperature (°C) | -27.4 | -28.4 | -21.2 | -15.6 | -1.7 | 10.2 | 9.8 | 12.0 | 8.9 | -13.1 | -11.5 | -10.5 |
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Daylight maximum duration (h) | 9.0 | 10.0 | 12.0 | 14.0 | 15.0 | 15.0 | 15.0 | 14.0 | 13.0 | 11.0 | 9.0 | 8.0 |
| Daylight mean duration (h) | 8.9 | 10.3 | 11.9 | 13.6 | 15.1 | 15.9 | 15.5 | 14.2 | 12.6 | 10.9 | 9.3 | 8.5 |
| Daylight minimum duration (h) | 8.0 | 9.0 | 11.0 | 12.0 | 14.0 | 15.0 | 15.0 | 13.0 | 11.0 | 10.0 | 8.0 | 8.0 |
| Sunshine mean duration (h) | 3.5 | 7.0 | 7.7 | 9.0 | 11.4 | 12.7 | 13.0 | 10.7 | 9.6 | 7.0 | 6.3 | 5.8 |
| Precipitation (mm) | 8 | 13 | 37 | 18 | 74 | 58 | 45 | 42 | 39 | 60 | 4 | 16 |
| Sunny days | 24 | 15 | 15 | 18 | 18 | 16 | 15 | 15 | 18 | 15 | 23 | 24 |
| Rainy days | 3 | 1 | 1 | 6 | 13 | 14 | 16 | 16 | 12 | 13 | 4 | 2 |
| Snow days | 4 | 12 | 15 | 6 | 0 | 0 | 0 | 0 | 0 | 3 | 3 | 5 |
The best time to visit McLean County during the most sunny months:
Months with the longest average daylight duration in McLean County:
The largest precipitation sum in McLean County is at