Dahlen, North Dakota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 29 °F (low) to 48.9 °F (high). Annual precipitation averages 21 Inches. Dahlen 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 | -3.1 °F | 14.1 °F | 0.52 in. |
| February | 0.5 °F | 19.2 °F | 0.47 in. |
| March | 14.0 °F | 31.6 °F | 0.74 in. |
| April | 28.8 °F | 49.7 °F | 0.92 in. |
| May | 42.1 °F | 64.7 °F | 2.91 in. |
| June | 53.6 °F | 74.0 °F | 3.96 in. |
| July | 57.5 °F | 78.7 °F | 3.44 in. |
| August | 55.0 °F | 78.1 °F | 2.72 in. |
| September | 45.6 °F | 69.1 °F | 2.13 in. |
| October | 32.4 °F | 53.0 °F | 1.74 in. |
| November | 17.6 °F | 34.4 °F | 0.77 in. |
| December | 4.5 °F | 19.9 °F | 0.64 in. |
| Annual | 29 °F | 48.9 °F | 20.96 in. |
| 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 : -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 |