Williamsville, New York has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 39.9 °F (low) to 57.2 °F (high). Annual precipitation averages 40.3 Inches. Williamsville is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 18.3 °F | 32.4 °F | 3.11 in. |
| February | 18.4 °F | 33.6 °F | 2.4 in. |
| March | 25.2 °F | 41.9 °F | 2.9 in. |
| April | 35.8 °F | 54.9 °F | 3.34 in. |
| May | 47.1 °F | 67.7 °F | 3.3 in. |
| June | 57.1 °F | 76.4 °F | 3.72 in. |
| July | 62.0 °F | 80.7 °F | 3.37 in. |
| August | 60.7 °F | 79.7 °F | 3.24 in. |
| September | 53.6 °F | 73.2 °F | 4.14 in. |
| October | 43.0 °F | 60.4 °F | 3.9 in. |
| November | 33.3 °F | 48.0 °F | 3.41 in. |
| December | 24.8 °F | 37.7 °F | 3.43 in. |
| Annual | 39.9 °F | 57.2 °F | 40.26 in. |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 6b : -5°F to 0°F |
| Plant Hardiness Zone - 2012 | Zone 6a : -10°F to -5°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |