Greenwich, New Jersey has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 46.9 °F (low) to 64.4 °F (high). Annual precipitation averages 44.7 Inches. Greenwich is located in USDA Plant Hardiness Zone 7b. 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 | 26.0 °F | 42.1 °F | 3.3 in. |
| February | 27.2 °F | 43.7 °F | 2.86 in. |
| March | 34.1 °F | 51.3 °F | 4.02 in. |
| April | 44.1 °F | 63.3 °F | 3.44 in. |
| May | 54.0 °F | 72.7 °F | 3.6 in. |
| June | 63.4 °F | 81.7 °F | 4.33 in. |
| July | 68.8 °F | 85.9 °F | 4.45 in. |
| August | 67.1 °F | 84.0 °F | 4.28 in. |
| September | 60.4 °F | 78.3 °F | 3.94 in. |
| October | 48.7 °F | 67.1 °F | 3.69 in. |
| November | 38.3 °F | 56.1 °F | 2.99 in. |
| December | 30.9 °F | 46.5 °F | 3.83 in. |
| Annual | 46.9 °F | 64.4 °F | 44.73 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 7b : 5°F to 10°F |
| Plant Hardiness Zone - 2012 | Zone 7a : 0°F to 5°F |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |