Somerville, Massachusetts has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 42.2 °F (low) to 60 °F (high). Annual precipitation averages 50.4 Inches. Somerville is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Nov. 1 - Nov. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 20.2 °F | 36.9 °F | 4.08 in. |
| February | 21.8 °F | 39.2 °F | 3.72 in. |
| March | 28.8 °F | 45.8 °F | 4.94 in. |
| April | 39.0 °F | 57.5 °F | 4.36 in. |
| May | 48.8 °F | 67.9 °F | 3.68 in. |
| June | 58.4 °F | 77.1 °F | 4.22 in. |
| July | 64.3 °F | 82.9 °F | 3.78 in. |
| August | 62.9 °F | 81.3 °F | 3.78 in. |
| September | 55.7 °F | 74.2 °F | 3.86 in. |
| October | 44.4 °F | 62.7 °F | 4.88 in. |
| November | 35.0 °F | 52.2 °F | 4.1 in. |
| December | 26.5 °F | 42.3 °F | 4.95 in. |
| Annual | 42.2 °F | 60 °F | 50.35 in. |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 6b : -5°F to 0°F |
| Plant Hardiness Zone - 2012 | Zone 6b : -5°F to 0°F |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |