Average annual temperature is 12.1 °C
Absolute maximum temperature: 35.6 °C
Absolute minimum temperature: -20.9 °C
Number of sunny days: 201 days
Number of rainy days: 145 days
Number of snow days: 19 days
Look at detailed online map of Rock Island County
* Weather data for Rock Island 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) | 13.9 | 12.0 | 22.5 | 25.9 | 32.7 | 34.5 | 34.8 | 35.6 | 32.6 | 29.5 | 18.6 | 14.5 |
| Average daytime temperature (°C) | 3.2 | 5.7 | 8.6 | 17.6 | 25.1 | 29.7 | 29.1 | 28.4 | 25.7 | 17.9 | 10.3 | 7.2 |
| Average temperature (°C) | -1.2 | 0.1 | 3.2 | 10.8 | 18.4 | 23.3 | 23.8 | 23.3 | 20.2 | 13.4 | 5.5 | 3.2 |
| Average night temperature (°C) | -4.2 | -4.5 | -0.7 | 5.4 | 12.1 | 17.1 | 18.8 | 18.9 | 15.9 | 9.6 | 1.5 | 0.7 |
| Absolute minimum temperature (°C) | -20.9 | -18.6 | -11.7 | -1.3 | 3.4 | 9.6 | 13.9 | 11.1 | 10.3 | -2.3 | -11.8 | -7.6 |
| 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 | 15.0 | 14.0 | 13.0 | 11.0 | 10.0 | 9.0 |
| Daylight mean duration (h) | 9.6 | 10.6 | 11.9 | 13.3 | 14.5 | 15.1 | 14.8 | 13.8 | 12.5 | 11.1 | 9.9 | 9.2 |
| 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) | 3.9 | 7.2 | 6.7 | 9.3 | 11.4 | 12.5 | 12.6 | 11.0 | 9.7 | 7.3 | 7.3 | 4.3 |
| Precipitation (mm) | 67 | 90 | 79 | 43 | 43 | 38 | 92 | 54 | 69 | 66 | 22 | 67 |
| Sunny days | 14 | 16 | 12 | 16 | 22 | 19 | 15 | 16 | 14 | 18 | 23 | 16 |
| Rainy days | 7 | 9 | 17 | 13 | 9 | 11 | 16 | 15 | 16 | 13 | 5 | 14 |
| Snow days | 10 | 3 | 2 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 2 | 1 |
The best time to visit Rock Island County during the most sunny months:
The largest precipitation sum in Rock Island County is at