| 2023 Hardiness Zone: | Zone 6a: -10°F to -5°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. 21 - Oct. 31 |
| Average Last Frost Date: | Apr. 21 - Apr. 30 |
| Koppen-Geiger Climate Zone: | Dfa - Humid Continental Hot Summers |
| Ecoregion: | 40a - Loess Flats and Till Plains |
| Heat Zone Days: | 46 - 60 days Over 86°F |
Annual Climate Data for ZIP Code 64601 - Chillicothe, MO | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 14 | 20 | 29 | 40 | 51 | 60 | 65 | 63 | 54 | 43 | 31 | 20 | 41 |
| Avg Max Temp (°F) | 33 | 41 | 53 | 65 | 75 | 84 | 89 | 88 | 80 | 69 | 51 | 39 | 64 |
| Avg Precip (In.) | 1.29 | 1.3 | 2.64 | 3.51 | 4.76 | 4.05 | 4.22 | 3.81 | 4.52 | 3.2 | 2.69 | 1.76 | 37.75 |