Donnybrook, North Dakota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 29.1 °F (low) to 50.9 °F (high). Annual precipitation averages 18.1 Inches. Donnybrook 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 | -0.0 °F | 18.0 °F | 0.52 in. |
| February | 3.9 °F | 22.7 °F | 0.49 in. |
| March | 15.2 °F | 34.6 °F | 0.66 in. |
| April | 28.1 °F | 52.0 °F | 1.06 in. |
| May | 41.2 °F | 65.3 °F | 2.63 in. |
| June | 52.0 °F | 73.8 °F | 3.81 in. |
| July | 55.8 °F | 79.8 °F | 2.81 in. |
| August | 53.5 °F | 80.7 °F | 1.97 in. |
| September | 44.1 °F | 70.6 °F | 1.57 in. |
| October | 31.5 °F | 53.9 °F | 1.42 in. |
| November | 17.7 °F | 36.0 °F | 0.56 in. |
| December | 5.7 °F | 22.9 °F | 0.55 in. |
| Annual | 29.1 °F | 50.9 °F | 18.05 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 |