| 2023 Hardiness Zone: | Zone 6a: -10°F to -5°F Zone 6b: -5°F to 0°F |
| 2012 Hardiness Zone: | Zone 6a: -10°F to -5°F Zone 5b: -15°F to -10°F |
| 1990 Hardiness Zone: | Zone 1b: -15F to -10F |
| 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: | 72i - Western Dissected Illinoian Till Plain |
| Heat Zone Days: | 46 - 60 days Over 86°F |
Annual Climate Data for ZIP Code 62650 - Jacksonville, IL | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 16 | 20 | 29 | 40 | 50 | 59 | 64 | 61 | 53 | 41 | 31 | 21 | 40 |
| Avg Max Temp (°F) | 34 | 40 | 52 | 64 | 75 | 83 | 87 | 85 | 79 | 68 | 52 | 39 | 63 |
| Avg Precip (In.) | 1.38 | 1.73 | 3.17 | 3.75 | 4.76 | 4.25 | 3.89 | 3.36 | 3.4 | 2.71 | 3.39 | 2.54 | 38.34 |