Roxbury, Vermont has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from -0.1 °C (low) to 10.8 °C (high). Annual precipitation averages 1173.5 Millimeters. Roxbury is located in USDA Plant Hardiness Zone 5a. 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 | -13.9 °C | -4.1 °C | 80.77 mm |
| February | -13.4 °C | -2.4 °C | 69.09 mm |
| March | -8.4 °C | 2.4 °C | 85.6 mm |
| April | -1.7 °C | 10 °C | 93.22 mm |
| May | 5.6 °C | 17.5 °C | 91.69 mm |
| June | 10 °C | 21.8 °C | 122.43 mm |
| July | 12.8 °C | 24.3 °C | 121.92 mm |
| August | 11.8 °C | 23.7 °C | 111.25 mm |
| September | 7.8 °C | 19.6 °C | 95.5 mm |
| October | 1.9 °C | 12.3 °C | 117.6 mm |
| November | -3.8 °C | 5.2 °C | 85.85 mm |
| December | -9.9 °C | -1 °C | 98.55 mm |
| Annual | -0.1 °C | 10.8 °C | 1173.47 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 5a : -28.9°C to -26.1°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 |