Sunderland, Massachusetts has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 2.2 °C (low) to 14 °C (high). Annual precipitation averages 1262.6 Millimeters. Sunderland is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -10.9 °C | -0.3 °C | 87.88 mm |
| February | -10.1 °C | 1.4 °C | 80.01 mm |
| March | -5.4 °C | 6.1 °C | 96.52 mm |
| April | 0.7 °C | 13.4 °C | 101.35 mm |
| May | 6.8 °C | 19.7 °C | 95.25 mm |
| June | 12.1 °C | 24.6 °C | 124.71 mm |
| July | 15.1 °C | 27.6 °C | 108.2 mm |
| August | 14 °C | 26.6 °C | 120.9 mm |
| September | 9.7 °C | 22.6 °C | 121.92 mm |
| October | 3.6 °C | 15.2 °C | 127 mm |
| November | -1.8 °C | 8.6 °C | 92.2 mm |
| December | -7 °C | 2.7 °C | 106.68 mm |
| Annual | 2.2 °C | 14 °C | 1262.62 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6a : -23.3°C to -20.6°C |
| Plant Hardiness Zone - 2012 | Zone 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |