Greenwich, Connecticut has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 45.3 °F (low) to 61.5 °F (high). Annual precipitation averages 49.6 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 | 24.3 °F | 38.8 °F | 3.96 in. |
| February | 25.0 °F | 40.9 °F | 2.91 in. |
| March | 31.7 °F | 47.6 °F | 4.16 in. |
| April | 41.5 °F | 59.2 °F | 4.05 in. |
| May | 51.0 °F | 69.2 °F | 3.8 in. |
| June | 60.8 °F | 78.1 °F | 4.58 in. |
| July | 66.7 °F | 83.9 °F | 3.96 in. |
| August | 65.8 °F | 81.8 °F | 4.61 in. |
| September | 58.6 °F | 75.8 °F | 4.78 in. |
| October | 48.4 °F | 64.4 °F | 4.48 in. |
| November | 38.8 °F | 53.8 °F | 3.91 in. |
| December | 31.0 °F | 44.1 °F | 4.43 in. |
| Annual | 45.3 °F | 61.5 °F | 49.63 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 | Dfa - Humid Continental Hot Summers With Year Around Precipitation |