Somerville, New Jersey has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 42.9 °F (low) to 63.4 °F (high). Annual precipitation averages 48.2 Inches. Somerville is located in USDA Plant Hardiness Zone 7a. 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 | 21.9 °F | 39.4 °F | 3.56 in. |
| February | 23.2 °F | 42.1 °F | 2.73 in. |
| March | 30.2 °F | 50.4 °F | 4.16 in. |
| April | 40.4 °F | 62.5 °F | 3.83 in. |
| May | 50.2 °F | 72.4 °F | 4.07 in. |
| June | 59.3 °F | 81.2 °F | 4.54 in. |
| July | 64.6 °F | 86.2 °F | 4.86 in. |
| August | 63.1 °F | 84.2 °F | 4.6 in. |
| September | 55.7 °F | 77.6 °F | 4.16 in. |
| October | 44.2 °F | 65.5 °F | 4.28 in. |
| November | 34.2 °F | 54.8 °F | 3.29 in. |
| December | 27.3 °F | 44.4 °F | 4.15 in. |
| Annual | 42.9 °F | 63.4 °F | 48.23 in. |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 7a : 0°F to 5°F |
| Plant Hardiness Zone - 2012 | Zone 6a : -10°F to -5°F |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |