McGrath, Minnesota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from -1 °C (low) to 10.6 °C (high). Annual precipitation averages 787.9 Millimeters. McGrath 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 | -6.9 °C | 18.03 mm |
| February | -16.1 °C | -3.8 °C | 20.07 mm |
| March | -8.9 °C | 3.1 °C | 37.08 mm |
| April | -1.3 °C | 10.8 °C | 65.28 mm |
| May | 5.2 °C | 18.3 °C | 87.63 mm |
| June | 10.7 °C | 23.4 °C | 114.55 mm |
| July | 13.4 °C | 25.9 °C | 117.35 mm |
| August | 12.2 °C | 24.8 °C | 99.57 mm |
| September | 7.9 °C | 20.4 °C | 80.52 mm |
| October | 1.6 °C | 12.3 °C | 77.47 mm |
| November | -5.5 °C | 3.3 °C | 41.66 mm |
| December | -12.9 °C | -3.9 °C | 28.7 mm |
| Annual | -1 °C | 10.6 °C | 787.91 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 3b : -37.2°C to -34.4°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |