McGregor, Minnesota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from -1.2 °C (low) to 10.6 °C (high). Annual precipitation averages 759.4 Millimeters. McGregor 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 °C | -7 °C | 19.56 mm |
| February | -16.2 °C | -3.8 °C | 18.54 mm |
| March | -9.1 °C | 3.2 °C | 33.27 mm |
| April | -1.6 °C | 10.7 °C | 59.94 mm |
| May | 5.1 °C | 18.2 °C | 90.42 mm |
| June | 10.6 °C | 23.4 °C | 117.09 mm |
| July | 13.2 °C | 25.9 °C | 113.79 mm |
| August | 11.9 °C | 24.7 °C | 93.73 mm |
| September | 7.5 °C | 20.3 °C | 78.99 mm |
| October | 1.2 °C | 12.2 °C | 72.64 mm |
| November | -5.7 °C | 3.2 °C | 34.8 mm |
| December | -13.1 °C | -4.1 °C | 26.67 mm |
| Annual | -1.2 °C | 10.6 °C | 759.44 mm |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 4a : -34.4°C to -31.7°C |
| Plant Hardiness Zone - 2012 | Zone 3b : -37.2°C to -34.4°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |