Hamilton, Missouri has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 41.7 °F (low) to 63.1 °F (high). Annual precipitation averages 39.9 Inches. Hamilton is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 16.3 °F | 35.3 °F | 1.11 in. |
| February | 19.9 °F | 40.7 °F | 1.59 in. |
| March | 30.4 °F | 52.7 °F | 2.68 in. |
| April | 40.0 °F | 63.6 °F | 3.92 in. |
| May | 51.9 °F | 73.3 °F | 5.83 in. |
| June | 61.6 °F | 82.5 °F | 5.22 in. |
| July | 65.9 °F | 87.2 °F | 4.05 in. |
| August | 63.8 °F | 85.8 °F | 4.33 in. |
| September | 54.6 °F | 78.0 °F | 4.19 in. |
| October | 42.8 °F | 66.2 °F | 3.26 in. |
| November | 31.4 °F | 52.4 °F | 2.1 in. |
| December | 21.4 °F | 39.8 °F | 1.63 in. |
| Annual | 41.7 °F | 63.1 °F | 39.91 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 5b : -15°F to -10°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 |