Heimdal, North Dakota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 29.4 °F (low) to 50.9 °F (high). Annual precipitation averages 19.6 Inches. Heimdal 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 | -0.7 °F | 17.6 °F | 0.41 in. |
| February | 2.5 °F | 21.8 °F | 0.43 in. |
| March | 15.2 °F | 34.2 °F | 0.67 in. |
| April | 28.6 °F | 52.0 °F | 1.13 in. |
| May | 41.7 °F | 66.0 °F | 2.71 in. |
| June | 52.9 °F | 74.7 °F | 3.8 in. |
| July | 57.1 °F | 80.2 °F | 3.29 in. |
| August | 54.3 °F | 80.1 °F | 2.34 in. |
| September | 45.3 °F | 71.0 °F | 2.08 in. |
| October | 32.2 °F | 54.7 °F | 1.45 in. |
| November | 17.9 °F | 36.5 °F | 0.67 in. |
| December | 5.5 °F | 22.4 °F | 0.63 in. |
| Annual | 29.4 °F | 50.9 °F | 19.61 in. |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 1 - May 10 |
| 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 |