Cornwall Bridge, Connecticut has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 37.6 °F (low) to 60 °F (high). Annual precipitation averages 46.7 Inches. Cornwall Bridge is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 15.1 °F | 34.9 °F | 3.22 in. |
| February | 16.8 °F | 38.0 °F | 2.62 in. |
| March | 24.6 °F | 46.0 °F | 3.51 in. |
| April | 35.0 °F | 59.6 °F | 3.5 in. |
| May | 45.6 °F | 70.7 °F | 3.77 in. |
| June | 54.5 °F | 78.6 °F | 4.61 in. |
| July | 60.0 °F | 83.7 °F | 4.73 in. |
| August | 58.2 °F | 81.8 °F | 4.31 in. |
| September | 50.8 °F | 74.1 °F | 4.49 in. |
| October | 39.4 °F | 62.3 °F | 4.7 in. |
| November | 29.7 °F | 50.7 °F | 3.35 in. |
| December | 21.7 °F | 39.5 °F | 3.91 in. |
| Annual | 37.6 °F | 60 °F | 46.72 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6a : -10°F to -5°F |
| Plant Hardiness Zone - 2012 | Zone 5b : -15°F to -10°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |