Washburn, North Dakota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from -0.8 °C (low) to 11.8 °C (high). Annual precipitation averages 458.7 Millimeters. Washburn is located in USDA Plant Hardiness Zone 4a. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -16.6 °C | -6.1 °C | 10.67 mm |
| February | -14.8 °C | -3.7 °C | 11.43 mm |
| March | -8.2 °C | 3.4 °C | 16.76 mm |
| April | -1.6 °C | 12.3 °C | 30.73 mm |
| May | 5.4 °C | 19.2 °C | 70.1 mm |
| June | 11.2 °C | 24.3 °C | 85.85 mm |
| July | 13.9 °C | 28 °C | 74.17 mm |
| August | 12.7 °C | 27.9 °C | 53.09 mm |
| September | 7.6 °C | 22.4 °C | 44.2 mm |
| October | 0.4 °C | 13.3 °C | 33.53 mm |
| November | -6.9 °C | 3.8 °C | 15.24 mm |
| December | -13.1 °C | -3.4 °C | 12.95 mm |
| Annual | -0.8 °C | 11.8 °C | 458.72 mm |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | Over 180 Days |
| Plant Hardiness Zone | Zone 4a : -34.4°C to -31.7°C |
| Plant Hardiness Zone - 2012 | Zone 4a : -34.4°C to -31.7°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |