Webster, Massachusetts has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 38.4 °F (low) to 59.5 °F (high). Annual precipitation averages 49.9 Inches. Webster is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 16.5 °F | 35.7 °F | 3.85 in. |
| February | 17.6 °F | 38.1 °F | 3.28 in. |
| March | 25.2 °F | 45.8 °F | 4.47 in. |
| April | 35.3 °F | 58.2 °F | 4.45 in. |
| May | 45.6 °F | 69.0 °F | 3.57 in. |
| June | 54.8 °F | 77.0 °F | 4.34 in. |
| July | 60.9 °F | 82.3 °F | 3.95 in. |
| August | 58.9 °F | 80.6 °F | 4.31 in. |
| September | 51.7 °F | 73.7 °F | 4.26 in. |
| October | 40.4 °F | 61.8 °F | 4.98 in. |
| November | 30.9 °F | 51.1 °F | 3.88 in. |
| December | 22.6 °F | 40.8 °F | 4.6 in. |
| Annual | 38.4 °F | 59.5 °F | 49.94 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 125-150 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 | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |