Groton, Vermont has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 32 °F (low) to 54.2 °F (high). Annual precipitation averages 42.1 Inches. Groton is located in USDA Plant Hardiness Zone 4b. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 6.1 °F | 26.5 °F | 2.72 in. |
| February | 6.8 °F | 30.1 °F | 2.31 in. |
| March | 16.7 °F | 39.2 °F | 2.78 in. |
| April | 29.7 °F | 52.8 °F | 3.31 in. |
| May | 41.7 °F | 65.9 °F | 3.98 in. |
| June | 50.8 °F | 74.3 °F | 4.01 in. |
| July | 56.1 °F | 79.5 °F | 4.28 in. |
| August | 53.9 °F | 78.0 °F | 4.2 in. |
| September | 46.5 °F | 70.6 °F | 3.75 in. |
| October | 35.5 °F | 56.9 °F | 4.35 in. |
| November | 25.8 °F | 44.1 °F | 3.05 in. |
| December | 14.8 °F | 32.4 °F | 3.37 in. |
| Annual | 32 °F | 54.2 °F | 42.11 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 4b : -25°F to -20°F |
| Plant Hardiness Zone - 2012 | Zone 4b : -25°F to -20°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |