McGregor, North Dakota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from -2.4 °C (low) to 10.1 °C (high). Annual precipitation averages 417.8 Millimeters. McGregor is located in USDA Plant Hardiness Zone 3b. The growing season typically runs from the last frost around May 21 - May 31 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -18.4 °C | -7.9 °C | 12.7 mm |
| February | -16.1 °C | -5.3 °C | 10.92 mm |
| March | -9.7 °C | 1.4 °C | 15.75 mm |
| April | -2.6 °C | 10.9 °C | 20.83 mm |
| May | 4.1 °C | 17.9 °C | 59.18 mm |
| June | 9.9 °C | 22.6 °C | 89.66 mm |
| July | 12.3 °C | 26.1 °C | 69.85 mm |
| August | 11.2 °C | 26.7 °C | 41.4 mm |
| September | 5.7 °C | 20.9 °C | 36.07 mm |
| October | -1.2 °C | 11.7 °C | 31.24 mm |
| November | -8.7 °C | 1.9 °C | 16 mm |
| December | -15.2 °C | -5.4 °C | 14.22 mm |
| Annual | -2.4 °C | 10.1 °C | 417.82 mm |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 21 - May 31 |
| Average Days With Frost | Over 180 Days |
| Plant Hardiness Zone | Zone 3b : -37.2°C to -34.4°C |
| Plant Hardiness Zone - 2012 | Zone 3b : -37.2°C to -34.4°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |