Northfield, Vermont has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 0.3 °C (low) to 12.6 °C (high). Annual precipitation averages 1131.3 Millimeters. Northfield is located in USDA Plant Hardiness Zone 4b. 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 | -14 °C | -2.7 °C | 76.2 mm |
| February | -13.4 °C | -0.7 °C | 62.99 mm |
| March | -8.1 °C | 4.2 °C | 83.06 mm |
| April | -0.9 °C | 11.7 °C | 88.65 mm |
| May | 5.6 °C | 19.4 °C | 95.5 mm |
| June | 10.7 °C | 24.1 °C | 116.08 mm |
| July | 13.4 °C | 26.7 °C | 123.19 mm |
| August | 12.4 °C | 25.8 °C | 106.17 mm |
| September | 8.2 °C | 21.8 °C | 90.93 mm |
| October | 2.2 °C | 14.1 °C | 112.01 mm |
| November | -3.1 °C | 6.9 °C | 82.04 mm |
| December | -9.3 °C | 0.3 °C | 94.49 mm |
| Annual | 0.3 °C | 12.6 °C | 1131.31 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| 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 |