Westfield, New York has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 42.1 °F (low) to 57.5 °F (high). Annual precipitation averages 42.1 Inches. Westfield 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 | 20.7 °F | 33.9 °F | 2.96 in. |
| February | 20.4 °F | 35.0 °F | 2.28 in. |
| March | 27.0 °F | 42.6 °F | 2.81 in. |
| April | 37.5 °F | 55.5 °F | 3.41 in. |
| May | 49.0 °F | 66.8 °F | 3.45 in. |
| June | 59.1 °F | 75.7 °F | 3.53 in. |
| July | 63.8 °F | 79.5 °F | 4.12 in. |
| August | 62.7 °F | 78.6 °F | 3.3 in. |
| September | 56.2 °F | 72.7 °F | 4.36 in. |
| October | 45.6 °F | 61.0 °F | 4.62 in. |
| November | 35.9 °F | 49.4 °F | 3.78 in. |
| December | 27.8 °F | 39.1 °F | 3.43 in. |
| Annual | 42.1 °F | 57.5 °F | 42.05 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 6b : -5°F to 0°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |