Chillicothe, Missouri has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 42.6 °F (low) to 63.6 °F (high). Annual precipitation averages 41 Inches. Chillicothe is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 16.8 °F | 35.5 °F | 1.29 in. |
| February | 20.9 °F | 41.0 °F | 1.78 in. |
| March | 31.0 °F | 52.9 °F | 2.76 in. |
| April | 41.7 °F | 64.2 °F | 3.79 in. |
| May | 53.1 °F | 74.0 °F | 5.47 in. |
| June | 63.0 °F | 83.5 °F | 5.13 in. |
| July | 67.0 °F | 87.6 °F | 4.73 in. |
| August | 64.5 °F | 86.2 °F | 4.48 in. |
| September | 55.5 °F | 79.1 °F | 4.39 in. |
| October | 43.3 °F | 66.8 °F | 3.21 in. |
| November | 31.9 °F | 52.7 °F | 2.32 in. |
| December | 22.0 °F | 40.2 °F | 1.65 in. |
| Annual | 42.6 °F | 63.6 °F | 41 in. |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 6a : -10°F to -5°F |
| Plant Hardiness Zone - 2012 | Zone 5b : -15°F to -10°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |