Fortuna, North Dakota has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 27.8 °F (low) to 50.4 °F (high). Annual precipitation averages 15.3 Inches. Fortuna 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 | -0.7 °F | 18.4 °F | 0.54 in. |
| February | 3.2 °F | 22.8 °F | 0.43 in. |
| March | 15.1 °F | 34.9 °F | 0.61 in. |
| April | 27.6 °F | 51.8 °F | 0.99 in. |
| May | 39.4 °F | 64.5 °F | 1.92 in. |
| June | 49.7 °F | 72.7 °F | 3.51 in. |
| July | 54.4 °F | 79.7 °F | 2.49 in. |
| August | 52.1 °F | 79.9 °F | 1.56 in. |
| September | 42.1 °F | 69.3 °F | 1.38 in. |
| October | 29.5 °F | 53.1 °F | 0.92 in. |
| November | 16.2 °F | 35.0 °F | 0.44 in. |
| December | 4.9 °F | 22.9 °F | 0.47 in. |
| Annual | 27.8 °F | 50.4 °F | 15.26 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 | BSk - Cold Semi-Arid Climate |