Wilmington, Massachusetts has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 40 °F (low) to 59.8 °F (high). Annual precipitation averages 49.3 Inches. Wilmington 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 | 17.7 °F | 35.7 °F | 3.82 in. |
| February | 19.5 °F | 38.4 °F | 3.54 in. |
| March | 26.8 °F | 45.6 °F | 4.71 in. |
| April | 37.0 °F | 58.0 °F | 4.25 in. |
| May | 47.0 °F | 68.2 °F | 3.74 in. |
| June | 56.4 °F | 77.2 °F | 4.27 in. |
| July | 62.3 °F | 83.1 °F | 3.83 in. |
| August | 60.8 °F | 81.6 °F | 3.75 in. |
| September | 53.3 °F | 74.5 °F | 3.84 in. |
| October | 41.8 °F | 62.3 °F | 4.83 in. |
| November | 32.6 °F | 51.6 °F | 3.96 in. |
| December | 24.2 °F | 41.3 °F | 4.79 in. |
| Annual | 40 °F | 59.8 °F | 49.33 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 | Severe Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |