Alsen, North Dakota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 27.5 °F (low) to 47.9 °F (high). Annual precipitation averages 20 Inches. Alsen is located in USDA Plant Hardiness Zone 3b. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Sep.11 - Sep. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -4.3 °F | 13.5 °F | 0.51 in. |
| February | -1.4 °F | 18.2 °F | 0.48 in. |
| March | 12.2 °F | 30.5 °F | 0.72 in. |
| April | 27.7 °F | 48.7 °F | 0.98 in. |
| May | 40.5 °F | 63.6 °F | 2.9 in. |
| June | 52.0 °F | 72.9 °F | 3.74 in. |
| July | 55.9 °F | 77.6 °F | 3.2 in. |
| August | 53.5 °F | 77.5 °F | 2.57 in. |
| September | 43.9 °F | 68.1 °F | 1.98 in. |
| October | 31.0 °F | 51.9 °F | 1.48 in. |
| November | 16.3 °F | 33.4 °F | 0.76 in. |
| December | 2.7 °F | 18.9 °F | 0.66 in. |
| Annual | 27.5 °F | 47.9 °F | 19.98 in. |
| Average First Frost Date | Sep.11 - Sep. 20 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | Over 180 Days |
| Plant Hardiness Zone | Zone 3b : -35°F to -30°F |
| Plant Hardiness Zone - 2012 | Zone 3b : -35°F to -30°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |