Northbridge, Massachusetts has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 39.2 °F (low) to 59.2 °F (high). Annual precipitation averages 49.3 Inches. Northbridge 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. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 17.1 °F | 35.3 °F | 3.86 in. |
| February | 18.3 °F | 37.9 °F | 3.5 in. |
| March | 25.9 °F | 45.4 °F | 4.73 in. |
| April | 36.2 °F | 57.8 °F | 4.5 in. |
| May | 46.6 °F | 68.4 °F | 3.46 in. |
| June | 55.8 °F | 76.6 °F | 4.1 in. |
| July | 61.7 °F | 81.9 °F | 3.75 in. |
| August | 60.0 °F | 80.4 °F | 3.99 in. |
| September | 52.6 °F | 73.6 °F | 3.88 in. |
| October | 41.5 °F | 61.8 °F | 4.86 in. |
| November | 31.7 °F | 51.0 °F | 3.84 in. |
| December | 23.3 °F | 40.7 °F | 4.87 in. |
| Annual | 39.2 °F | 59.2 °F | 49.34 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| 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 | Moderate Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |