Grand Forks, North Dakota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from -1 °C (low) to 10 °C (high). Annual precipitation averages 563.6 Millimeters. Grand Forks 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 Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -19.2 °C | -9.4 °C | 14.99 mm |
| February | -17.2 °C | -6.8 °C | 14.22 mm |
| March | -9.3 °C | 0.5 °C | 22.35 mm |
| April | -0.8 °C | 10.7 °C | 27.18 mm |
| May | 6.2 °C | 18.9 °C | 71.63 mm |
| June | 12.7 °C | 24.2 °C | 96.77 mm |
| July | 14.7 °C | 26.6 °C | 87.38 mm |
| August | 13.1 °C | 26.3 °C | 76.96 mm |
| September | 8.1 °C | 21.2 °C | 64.01 mm |
| October | 1.2 °C | 12.3 °C | 48.51 mm |
| November | -7 °C | 2.2 °C | 20.32 mm |
| December | -14.6 °C | -6.2 °C | 19.3 mm |
| Annual | -1 °C | 10 °C | 563.62 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| 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 | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |