Bristol, Vermont has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 34.2 °F (low) to 54.9 °F (high). Annual precipitation averages 42.9 Inches. Bristol 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 Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 9.0 °F | 27.8 °F | 2.75 in. |
| February | 9.7 °F | 30.6 °F | 2.1 in. |
| March | 19.0 °F | 39.5 °F | 2.64 in. |
| April | 31.6 °F | 53.5 °F | 3.41 in. |
| May | 43.4 °F | 66.8 °F | 3.92 in. |
| June | 52.7 °F | 75.1 °F | 4.36 in. |
| July | 57.9 °F | 80.0 °F | 5.21 in. |
| August | 55.9 °F | 78.1 °F | 4.45 in. |
| September | 48.3 °F | 70.9 °F | 3.62 in. |
| October | 37.4 °F | 57.4 °F | 4.12 in. |
| November | 28.0 °F | 45.1 °F | 3.2 in. |
| December | 17.1 °F | 33.7 °F | 3.1 in. |
| Annual | 34.2 °F | 54.9 °F | 42.88 in. |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 150-180 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 |