Windsor, Connecticut has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 4.9 °C (low) to 15.8 °C (high). Annual precipitation averages 1282 Millimeters. 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 | -7.5 °C | 1.8 °C | 92.2 mm |
| February | -6.8 °C | 3.4 °C | 81.79 mm |
| March | -2.4 °C | 7.9 °C | 107.7 mm |
| April | 3.6 °C | 15.2 °C | 104.39 mm |
| May | 9.3 °C | 21.3 °C | 94.49 mm |
| June | 14.4 °C | 26.1 °C | 114.05 mm |
| July | 17.4 °C | 29 °C | 107.19 mm |
| August | 16.5 °C | 28.1 °C | 109.47 mm |
| September | 12.3 °C | 24.1 °C | 119.13 mm |
| October | 5.9 °C | 17.2 °C | 135.38 mm |
| November | 0.4 °C | 10.7 °C | 100.08 mm |
| December | -4.1 °C | 4.8 °C | 116.08 mm |
| Annual | 4.9 °C | 15.8 °C | 1281.95 mm |
| 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 : -20.6°C to -17.8°C |
| Plant Hardiness Zone - 2012 | Zone 6b : -20.6°C to -17.8°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |