Washburn, Maine has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 29.9 °F (low) to 50.2 °F (high). Annual precipitation averages 40.6 Inches. Washburn is located in USDA Plant Hardiness Zone 4a. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 0.2 °F | 21.0 °F | 3.21 in. |
| February | 1.6 °F | 24.0 °F | 2.41 in. |
| March | 13.4 °F | 33.9 °F | 2.74 in. |
| April | 28.2 °F | 47.4 °F | 3.04 in. |
| May | 40.2 °F | 62.5 °F | 3.33 in. |
| June | 49.7 °F | 71.9 °F | 3.98 in. |
| July | 55.5 °F | 76.7 °F | 3.91 in. |
| August | 53.4 °F | 75.8 °F | 3.58 in. |
| September | 45.6 °F | 67.7 °F | 3.41 in. |
| October | 34.9 °F | 53.5 °F | 4.12 in. |
| November | 25.0 °F | 39.9 °F | 3.34 in. |
| December | 11.1 °F | 27.9 °F | 3.56 in. |
| Annual | 29.9 °F | 50.2 °F | 40.63 in. |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 4a : -30°F to -25°F |
| Plant Hardiness Zone - 2012 | Zone 4a : -30°F to -25°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |