Williamsville, Missouri has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 46.1 °F (low) to 68.6 °F (high). Annual precipitation averages 49.5 Inches. Williamsville is located in USDA Plant Hardiness Zone 7a. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 24.2 °F | 43.8 °F | 3.4 in. |
| February | 27.2 °F | 49.1 °F | 3.41 in. |
| March | 35.6 °F | 58.8 °F | 4.63 in. |
| April | 45.5 °F | 70.2 °F | 5.48 in. |
| May | 55.5 °F | 78.1 °F | 5.5 in. |
| June | 64.3 °F | 86.3 °F | 3.6 in. |
| July | 68.2 °F | 89.4 °F | 4.2 in. |
| August | 66.1 °F | 88.8 °F | 3.73 in. |
| September | 58.0 °F | 82.2 °F | 3.49 in. |
| October | 45.7 °F | 71.4 °F | 3.52 in. |
| November | 35.4 °F | 57.9 °F | 4.58 in. |
| December | 27.5 °F | 46.8 °F | 3.98 in. |
| Annual | 46.1 °F | 68.6 °F | 49.52 in. |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 7a : 0°F to 5°F |
| Plant Hardiness Zone - 2012 | Zone 6b : -5°F to 0°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |