West Boylston, Massachusetts has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 38.3 °F (low) to 58.9 °F (high). Annual precipitation averages 49.5 Inches. West Boylston is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 15.5 °F | 34.2 °F | 3.79 in. |
| February | 16.8 °F | 36.9 °F | 3.32 in. |
| March | 24.8 °F | 44.5 °F | 4.54 in. |
| April | 35.4 °F | 57.5 °F | 4.25 in. |
| May | 46.3 °F | 68.3 °F | 3.68 in. |
| June | 55.7 °F | 76.7 °F | 4.23 in. |
| July | 61.4 °F | 82.2 °F | 3.91 in. |
| August | 59.7 °F | 80.7 °F | 4.23 in. |
| September | 51.5 °F | 73.8 °F | 4.07 in. |
| October | 40.1 °F | 61.8 °F | 5.09 in. |
| November | 30.6 °F | 50.3 °F | 3.83 in. |
| December | 22.1 °F | 39.9 °F | 4.55 in. |
| Annual | 38.3 °F | 58.9 °F | 49.49 in. |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6a : -10°F to -5°F |
| Plant Hardiness Zone - 2012 | Zone 6a : -10°F to -5°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |