| 2023 Hardiness Zone: | Zone 6b: -5°F to 0°F |
| 2012 Hardiness Zone: | Zone 6a: -10°F to -5°F Zone 6b: -5°F to 0°F |
| 1990 Hardiness Zone: | Zone 6a: -10F to -5F |
| 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: | 72j - Southern Illinoian Till Plain |
| Heat Zone Days: | 46 - 60 days Over 86°F |
Annual Climate Data for ZIP Code 62801 - Centralia, IL | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 19 | 24 | 34 | 44 | 54 | 63 | 67 | 65 | 57 | 45 | 35 | 25 | 44 |
| Avg Max Temp (°F) | 37 | 43 | 54 | 66 | 75 | 84 | 88 | 86 | 80 | 69 | 54 | 42 | 65 |
| Avg Precip (In.) | 2.47 | 2.63 | 3.91 | 4.49 | 4.54 | 4.1 | 3.9 | 2.81 | 3.09 | 3.24 | 4.08 | 3.19 | 42.47 |