Derby Line, Vermont has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from -0.1 °C (low) to 11 °C (high). Annual precipitation averages 1209.6 Millimeters. Derby Line is located in USDA Plant Hardiness Zone 4b. The growing season typically runs from the last frost around May 21 - May 31 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -15.2 °C | -4.5 °C | 83.57 mm |
| February | -14.4 °C | -2.9 °C | 69.09 mm |
| March | -8.8 °C | 2.2 °C | 78.99 mm |
| April | -1.3 °C | 10.1 °C | 90.68 mm |
| May | 5.4 °C | 17.8 °C | 108.46 mm |
| June | 10.7 °C | 22.6 °C | 130.81 mm |
| July | 13.3 °C | 25.1 °C | 124.97 mm |
| August | 12.4 °C | 24.2 °C | 114.55 mm |
| September | 8.1 °C | 20.1 °C | 97.79 mm |
| October | 2.3 °C | 12.6 °C | 117.86 mm |
| November | -3.4 °C | 5.3 °C | 91.69 mm |
| December | -9.9 °C | -0.9 °C | 101.09 mm |
| Annual | -0.1 °C | 11 °C | 1209.55 mm |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 21 - May 31 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 4b : -31.7°C to -28.9°C |
| Plant Hardiness Zone - 2012 | Zone 4a : -34.4°C to -31.7°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |