Windsor, Maine has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 35.7 °F (low) to 54.9 °F (high). Annual precipitation averages 47.3 Inches. Windsor is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 10.3 °F | 29.0 °F | 3.5 in. |
| February | 12.2 °F | 32.1 °F | 3.08 in. |
| March | 21.8 °F | 40.2 °F | 3.83 in. |
| April | 33.0 °F | 52.8 °F | 4.19 in. |
| May | 43.7 °F | 64.6 °F | 3.57 in. |
| June | 53.2 °F | 73.3 °F | 4.29 in. |
| July | 59.1 °F | 78.9 °F | 3.37 in. |
| August | 57.6 °F | 78.1 °F | 3.52 in. |
| September | 50.0 °F | 70.7 °F | 3.88 in. |
| October | 39.1 °F | 57.9 °F | 5.33 in. |
| November | 29.2 °F | 45.9 °F | 4.4 in. |
| December | 18.6 °F | 35.0 °F | 4.35 in. |
| Annual | 35.7 °F | 54.9 °F | 47.31 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5b : -15°F to -10°F |
| Plant Hardiness Zone - 2012 | Zone 5a : -20°F to -15°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |