Dorchester, New Jersey has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 46.3 °F (low) to 64.6 °F (high). Annual precipitation averages 46.1 Inches. Dorchester is located in USDA Plant Hardiness Zone 7b. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 25.7 °F | 42.8 °F | 3.34 in. |
| February | 26.4 °F | 44.8 °F | 3.02 in. |
| March | 33.0 °F | 51.6 °F | 4.39 in. |
| April | 43.1 °F | 63.1 °F | 3.49 in. |
| May | 52.6 °F | 72.2 °F | 3.51 in. |
| June | 62.3 °F | 81.1 °F | 3.91 in. |
| July | 67.7 °F | 85.7 °F | 4.55 in. |
| August | 66.0 °F | 83.8 °F | 4.67 in. |
| September | 60.3 °F | 78.2 °F | 3.87 in. |
| October | 49.0 °F | 67.3 °F | 4.05 in. |
| November | 38.6 °F | 56.9 °F | 3.21 in. |
| December | 30.9 °F | 47.6 °F | 4.13 in. |
| Annual | 46.3 °F | 64.6 °F | 46.14 in. |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 7b : 5°F to 10°F |
| Plant Hardiness Zone - 2012 | Zone 6b : -5°F to 0°F |
| Current Drought Conditions | Extreme Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |