New London, Connecticut has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 43.2 °F (low) to 59.5 °F (high). Annual precipitation averages 48 Inches. New London 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 | 22.0 °F | 38.3 °F | 3.8 in. |
| February | 23.5 °F | 40.1 °F | 3.24 in. |
| March | 30.1 °F | 46.4 °F | 4.77 in. |
| April | 39.6 °F | 56.3 °F | 4.49 in. |
| May | 48.7 °F | 65.6 °F | 3.67 in. |
| June | 58.2 °F | 74.7 °F | 3.84 in. |
| July | 64.7 °F | 80.2 °F | 3.17 in. |
| August | 63.6 °F | 79.2 °F | 3.82 in. |
| September | 56.6 °F | 73.5 °F | 4.13 in. |
| October | 46.4 °F | 63.0 °F | 4.59 in. |
| November | 36.7 °F | 53.1 °F | 3.87 in. |
| December | 28.3 °F | 44.0 °F | 4.65 in. |
| Annual | 43.2 °F | 59.5 °F | 48.04 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 6b : -5°F to 0°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |