Grace City, North Dakota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from -1.2 °C (low) to 10.4 °C (high). Annual precipitation averages 522 Millimeters. Grace City 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 | -18.2 °C | -8.4 °C | 12.7 mm |
| February | -16.2 °C | -5.8 °C | 11.43 mm |
| March | -9.2 °C | 1.2 °C | 19.56 mm |
| April | -1.6 °C | 10.8 °C | 26.67 mm |
| May | 5.7 °C | 18.8 °C | 66.04 mm |
| June | 12 °C | 23.9 °C | 95.25 mm |
| July | 14.3 °C | 26.7 °C | 92.2 mm |
| August | 12.8 °C | 26.3 °C | 66.55 mm |
| September | 7.7 °C | 21.4 °C | 51.56 mm |
| October | 0.5 °C | 12.4 °C | 41.91 mm |
| November | -7.4 °C | 2.4 °C | 19.56 mm |
| December | -14.3 °C | -5.5 °C | 18.54 mm |
| Annual | -1.2 °C | 10.4 °C | 521.97 mm |
| 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 : -34.4°C to -31.7°C |
| Plant Hardiness Zone - 2012 | Zone 4a : -34.4°C to -31.7°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |