Washington, Vermont has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 32.2 °F (low) to 50.5 °F (high). Annual precipitation averages 46.8 Inches. Washington 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 | 7.3 °F | 23.3 °F | 2.89 in. |
| February | 7.4 °F | 26.3 °F | 2.41 in. |
| March | 17.2 °F | 34.8 °F | 3.19 in. |
| April | 29.3 °F | 49.0 °F | 3.48 in. |
| May | 43.2 °F | 62.3 °F | 3.79 in. |
| June | 50.3 °F | 70.8 °F | 4.79 in. |
| July | 56.0 °F | 75.1 °F | 5.5 in. |
| August | 54.4 °F | 74.0 °F | 5.19 in. |
| September | 47.1 °F | 66.9 °F | 3.9 in. |
| October | 35.9 °F | 53.8 °F | 4.44 in. |
| November | 25.0 °F | 40.2 °F | 3.42 in. |
| December | 13.1 °F | 29.0 °F | 3.81 in. |
| Annual | 32.2 °F | 50.5 °F | 46.81 in. |
| 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 : -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 |