| 2023 Hardiness Zone: | Zone 6b: -5°F to 0°F Zone 7a: 0°F to 5°F |
| 2012 Hardiness Zone: | Zone 6b: -5°F to 0°F |
| 1990 Hardiness Zone: | Zone 6a: -10F to -5F |
| 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: | 72j - Southern Illinoian Till Plain |
| Heat Zone Days: | 61 - 90 days Over 86°F |
Annual Climate Data for ZIP Code 62286 - Sparta, IL | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 21 | 25 | 34 | 44 | 53 | 63 | 67 | 65 | 56 | 45 | 36 | 26 | 44 |
| Avg Max Temp (°F) | 38 | 45 | 55 | 66 | 76 | 84 | 89 | 87 | 80 | 69 | 55 | 43 | 66 |
| Avg Precip (In.) | 2.36 | 2.55 | 4.02 | 4.09 | 4.49 | 3.75 | 4.12 | 3.33 | 3.13 | 3.22 | 4.21 | 3.32 | 42.59 |