Waterbury, Vermont has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 0.4 °C (low) to 12.9 °C (high). Annual precipitation averages 1135.4 Millimeters. Waterbury is located in USDA Plant Hardiness Zone 4b. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -14.4 °C | -2.8 °C | 72.64 mm |
| February | -14.2 °C | -0.9 °C | 61.98 mm |
| March | -8.2 °C | 4.2 °C | 80.52 mm |
| April | -0.6 °C | 11.9 °C | 91.44 mm |
| May | 5.9 °C | 19.7 °C | 101.09 mm |
| June | 11.2 °C | 24.6 °C | 121.67 mm |
| July | 13.9 °C | 27.3 °C | 115.32 mm |
| August | 12.8 °C | 26.5 °C | 113.79 mm |
| September | 8.8 °C | 22.3 °C | 98.55 mm |
| October | 2.4 °C | 14.4 °C | 108.97 mm |
| November | -3.1 °C | 7.2 °C | 79.5 mm |
| December | -9.4 °C | 0.3 °C | 89.92 mm |
| Annual | 0.4 °C | 12.9 °C | 1135.39 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 4b : -31.7°C to -28.9°C |
| Plant Hardiness Zone - 2012 | Zone 4b : -31.7°C to -28.9°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |