Windsor, Connecticut has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 40.9 °F (low) to 60.5 °F (high). Annual precipitation averages 50.5 Inches. Windsor is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 18.5 °F | 35.3 °F | 3.63 in. |
| February | 19.8 °F | 38.1 °F | 3.22 in. |
| March | 27.6 °F | 46.3 °F | 4.24 in. |
| April | 38.4 °F | 59.4 °F | 4.11 in. |
| May | 48.8 °F | 70.4 °F | 3.72 in. |
| June | 58.0 °F | 78.9 °F | 4.49 in. |
| July | 63.4 °F | 84.2 °F | 4.22 in. |
| August | 61.7 °F | 82.5 °F | 4.31 in. |
| September | 54.2 °F | 75.3 °F | 4.69 in. |
| October | 42.7 °F | 63.0 °F | 5.33 in. |
| November | 32.8 °F | 51.3 °F | 3.94 in. |
| December | 24.7 °F | 40.7 °F | 4.57 in. |
| Annual | 40.9 °F | 60.5 °F | 50.47 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6b : -5°F to 0°F |
| Plant Hardiness Zone - 2012 | Zone 6b : -5°F to 0°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |