McGrath, Minnesota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 30.2 °F (low) to 51.1 °F (high). Annual precipitation averages 31 Inches. 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 | -0.4 °F | 19.6 °F | 0.71 in. |
| February | 3.1 °F | 25.2 °F | 0.79 in. |
| March | 15.9 °F | 37.5 °F | 1.46 in. |
| April | 29.6 °F | 51.4 °F | 2.57 in. |
| May | 41.3 °F | 64.9 °F | 3.45 in. |
| June | 51.2 °F | 74.1 °F | 4.51 in. |
| July | 56.2 °F | 78.6 °F | 4.62 in. |
| August | 54.0 °F | 76.7 °F | 3.92 in. |
| September | 46.3 °F | 68.7 °F | 3.17 in. |
| October | 34.8 °F | 54.1 °F | 3.05 in. |
| November | 22.1 °F | 38.0 °F | 1.64 in. |
| December | 8.8 °F | 24.9 °F | 1.13 in. |
| Annual | 30.2 °F | 51.1 °F | 31.02 in. |
| 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 : -30°F to -25°F |
| Plant Hardiness Zone - 2012 | Zone 3b : -35°F to -30°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |