| 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 |
| 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: | 72m - Wabash River Bluffs and Low Hills |
| Heat Zone Days: | 46 - 60 days Over 86°F |
Annual Climate Data for ZIP Code 62441 - Marshall, IL | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 19 | 23 | 32 | 42 | 52 | 60 | 64 | 62 | 54 | 43 | 34 | 24 | 42 |
| Avg Max Temp (°F) | 36 | 42 | 53 | 65 | 75 | 84 | 87 | 85 | 79 | 69 | 53 | 41 | 64 |
| Avg Precip (In.) | 2.27 | 2.36 | 3.54 | 3.99 | 4.48 | 4.03 | 4.48 | 3.66 | 3.19 | 2.93 | 3.88 | 3.05 | 41.88 |