Fairmount, North Dakota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 32.3 °F (low) to 52.5 °F (high). Annual precipitation averages 25.4 Inches. Fairmount is located in USDA Plant Hardiness Zone 4a. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 0.8 °F | 18.7 °F | 0.71 in. |
| February | 4.3 °F | 23.1 °F | 0.65 in. |
| March | 18.3 °F | 36.1 °F | 1.08 in. |
| April | 32.1 °F | 53.3 °F | 2.06 in. |
| May | 45.2 °F | 67.7 °F | 3.12 in. |
| June | 56.4 °F | 77.1 °F | 4.15 in. |
| July | 60.2 °F | 81.5 °F | 3.81 in. |
| August | 57.0 °F | 80.1 °F | 2.89 in. |
| September | 48.2 °F | 71.9 °F | 2.82 in. |
| October | 35.3 °F | 56.6 °F | 2.45 in. |
| November | 21.5 °F | 39.2 °F | 0.89 in. |
| December | 8.3 °F | 24.9 °F | 0.79 in. |
| Annual | 32.3 °F | 52.5 °F | 25.42 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| 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 |