Winsted, Connecticut has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 3 °C (low) to 15 °C (high). Annual precipitation averages 1350.3 Millimeters. Winsted 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 | -9.4 °C | 1.1 °C | 95.5 mm |
| February | -8.7 °C | 2.8 °C | 83.57 mm |
| March | -4.4 °C | 7.2 °C | 113.03 mm |
| April | 1.3 °C | 14.7 °C | 103.63 mm |
| May | 7.2 °C | 20.8 °C | 105.92 mm |
| June | 12.6 °C | 25.4 °C | 123.19 mm |
| July | 15.4 °C | 28.1 °C | 116.84 mm |
| August | 14.4 °C | 27 °C | 119.13 mm |
| September | 10.3 °C | 23.1 °C | 127.51 mm |
| October | 4.1 °C | 16.2 °C | 139.45 mm |
| November | -1.2 °C | 9.8 °C | 103.12 mm |
| December | -5.7 °C | 3.8 °C | 119.38 mm |
| Annual | 3 °C | 15 °C | 1350.27 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 6a : -23.3°C to -20.6°C |
| Plant Hardiness Zone - 2012 | Zone 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |