Winooski, Vermont has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 37.2 °F (low) to 55.7 °F (high). Annual precipitation averages 39.8 Inches. Winooski is located in USDA Plant Hardiness Zone 5a. 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 | 10.4 °F | 27.9 °F | 2.33 in. |
| February | 11.9 °F | 30.7 °F | 1.84 in. |
| March | 21.6 °F | 39.5 °F | 2.49 in. |
| April | 34.6 °F | 54.2 °F | 3.21 in. |
| May | 46.8 °F | 67.8 °F | 3.53 in. |
| June | 56.5 °F | 76.4 °F | 4.28 in. |
| July | 61.6 °F | 81.0 °F | 4.45 in. |
| August | 59.8 °F | 79.9 °F | 4.03 in. |
| September | 51.9 °F | 72.0 °F | 3.89 in. |
| October | 40.7 °F | 58.3 °F | 3.99 in. |
| November | 30.7 °F | 45.9 °F | 2.93 in. |
| December | 19.3 °F | 34.3 °F | 2.78 in. |
| Annual | 37.2 °F | 55.7 °F | 39.75 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 5a : -20°F to -15°F |
| Plant Hardiness Zone - 2012 | Zone 5a : -20°F to -15°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |