Fairfield, Vermont has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 35.1 °F (low) to 54.5 °F (high). Annual precipitation averages 41.7 Inches. Fairfield is located in USDA Plant Hardiness Zone 5a. 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 | 7.7 °F | 26.6 °F | 2.56 in. |
| February | 9.3 °F | 29.4 °F | 2.19 in. |
| March | 19.5 °F | 38.6 °F | 2.75 in. |
| April | 32.5 °F | 53.1 °F | 3.32 in. |
| May | 45.0 °F | 67.0 °F | 3.67 in. |
| June | 54.4 °F | 75.1 °F | 4.36 in. |
| July | 59.5 °F | 79.5 °F | 4.32 in. |
| August | 57.6 °F | 78.5 °F | 4.21 in. |
| September | 50.2 °F | 70.9 °F | 3.95 in. |
| October | 39.4 °F | 57.6 °F | 4.06 in. |
| November | 29.1 °F | 44.8 °F | 3.16 in. |
| December | 17.1 °F | 33.1 °F | 3.17 in. |
| Annual | 35.1 °F | 54.5 °F | 41.72 in. |
| 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 5a : -20°F to -15°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 |