| 2023 Hardiness Zone: | Zone 6b: -5°F to 0°F |
| 2012 Hardiness Zone: | Zone 6a: -10°F to -5°F |
| 1990 Hardiness Zone: | Zone 1b: -15F to -10F |
| Average First Frost Date: | Oct. 21 - Oct. 31 |
| Average Last Frost Date: | Apr. 11 - Apr. 20 |
| Koppen-Geiger Climate Zone: | Dfa - Humid Continental Hot Summers |
| Ecoregion: | 72i - Western Dissected Illinoian Till Plain |
| Heat Zone Days: | 61 - 90 days Over 86°F |
Annual Climate Data for ZIP Code 62033 - Gillespie, IL | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 18 | 23 | 32 | 43 | 53 | 62 | 66 | 64 | 56 | 45 | 34 | 23 | 43 |
| Avg Max Temp (°F) | 35 | 42 | 53 | 65 | 75 | 84 | 88 | 86 | 80 | 68 | 53 | 40 | 64 |
| Avg Precip (In.) | 2.05 | 2.1 | 3.46 | 3.89 | 4.25 | 3.7 | 3.63 | 3.34 | 3.09 | 2.74 | 3.69 | 2.9 | 38.83 |