| 2023 Hardiness Zone: | Zone 5b: -15°F to -10°F | |
| 2012 Hardiness Zone: | Zone 5b: -15°F to -10°F | |
| 1990 Hardiness Zone: | Zone 5a: -20F to -15F | |
| Average First Frost Date: | Oct. 11 - Oct. 20 | |
| Average Last Frost Date: | Apr. 21 - Apr. 30 | |
| Koppen-Geiger Climate Zone: | Dfa - Humid Continental Hot Summers | |
| Ecoregion: | 54a - Illinois/Indiana Prairies | |
| Current Drought Status: | Exceptional Drought | |
| Heat Zone Days: | 1 - 7 days Over 86°F |
Annual Climate Data for ZIP Code 61274 - Osco, IL | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 12 | 18 | 28 | 39 | 50 | 60 | 64 | 62 | 54 | 42 | 30 | 18 | 40 |
| Avg Max Temp (°F) | 29 | 35 | 47 | 61 | 72 | 82 | 85 | 83 | 76 | 64 | 47 | 34 | 59 |
| Avg Precip (In.) | 1.46 | 1.45 | 2.67 | 3.66 | 4.14 | 4.37 | 3.99 | 4.28 | 3.3 | 2.78 | 2.71 | 2.14 | 36.97 |