| 2023 Hardiness Zone: | Zone 5a: -20°F to -15°F Zone 5b: -15°F to -10°F | |
| 2012 Hardiness Zone: | Zone 5a: -20°F to -15°F Zone 5b: -15°F to -10°F | |
| 1990 Hardiness Zone: | Zone 5a: -20F to -15F | |
| Average First Frost Date: | Oct. 1 - Oct. 10 | |
| Average Last Frost Date: | May 1 - May 10 | |
| Koppen-Geiger Climate Zone: | Dfa - Humid Continental Hot Summers | |
| Ecoregion: | 54g - Rock River Hills | |
| Current Drought Status: | Exceptional Drought | |
| Heat Zone Days: | 8 - 14 days Over 86°F |
Annual Climate Data for ZIP Code 61081 - Sterling, IL | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 10 | 16 | 27 | 38 | 49 | 59 | 63 | 60 | 52 | 40 | 29 | 17 | 38 |
| Avg Max Temp (°F) | 28 | 33 | 46 | 60 | 72 | 81 | 84 | 82 | 75 | 63 | 47 | 33 | 59 |
| Avg Precip (In.) | 1.46 | 1.41 | 2.57 | 3.57 | 4.24 | 4.61 | 3.64 | 4.43 | 3.24 | 2.72 | 2.72 | 2.05 | 36.66 |