Fenwick, Connecticut has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 44.8 °F (low) to 60.5 °F (high). Annual precipitation averages 49.2 Inches. Fenwick 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 | 24.5 °F | 39.0 °F | 3.68 in. |
| February | 25.3 °F | 40.3 °F | 3.32 in. |
| March | 31.1 °F | 46.5 °F | 4.6 in. |
| April | 40.0 °F | 57.8 °F | 4.6 in. |
| May | 49.0 °F | 66.8 °F | 3.72 in. |
| June | 58.7 °F | 75.5 °F | 4.27 in. |
| July | 65.5 °F | 81.6 °F | 3.39 in. |
| August | 65.1 °F | 80.2 °F | 4.18 in. |
| September | 58.9 °F | 75.1 °F | 4.31 in. |
| October | 48.9 °F | 64.4 °F | 4.61 in. |
| November | 39.4 °F | 53.9 °F | 3.97 in. |
| December | 31.0 °F | 44.6 °F | 4.54 in. |
| Annual | 44.8 °F | 60.5 °F | 49.19 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 7a : 0°F to 5°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |