Walhalla, North Dakota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 29 °F (low) to 49 °F (high). Annual precipitation averages 22 Inches. Walhalla 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 | -2.5 °F | 14.2 °F | 0.61 in. |
| February | 0.6 °F | 19.1 °F | 0.57 in. |
| March | 14.3 °F | 31.5 °F | 0.81 in. |
| April | 28.3 °F | 50.0 °F | 0.98 in. |
| May | 41.2 °F | 64.7 °F | 3.23 in. |
| June | 53.0 °F | 74.4 °F | 3.74 in. |
| July | 57.3 °F | 78.5 °F | 3.3 in. |
| August | 54.0 °F | 78.5 °F | 2.7 in. |
| September | 45.3 °F | 69.2 °F | 2.42 in. |
| October | 33.1 °F | 52.8 °F | 1.77 in. |
| November | 18.6 °F | 34.8 °F | 1.04 in. |
| December | 4.6 °F | 20.1 °F | 0.84 in. |
| Annual | 29 °F | 49 °F | 22.01 in. |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | Over 180 Days |
| Plant Hardiness Zone | Zone 4a : -30°F to -25°F |
| Plant Hardiness Zone - 2012 | Zone 3b : -35°F to -30°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |