McHenry, North Dakota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from -1.2 °C (low) to 10.3 °C (high). Annual precipitation averages 538.5 Millimeters. McHenry 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 | -18.3 °C | -8.6 °C | 13.72 mm |
| February | -16.3 °C | -5.9 °C | 11.68 mm |
| March | -9.2 °C | 1.1 °C | 21.08 mm |
| April | -1.6 °C | 10.8 °C | 26.16 mm |
| May | 5.7 °C | 18.8 °C | 68.58 mm |
| June | 11.9 °C | 23.9 °C | 97.79 mm |
| July | 14.3 °C | 26.7 °C | 94.49 mm |
| August | 12.8 °C | 26.3 °C | 67.06 mm |
| September | 7.7 °C | 21.4 °C | 52.32 mm |
| October | 0.4 °C | 12.3 °C | 43.18 mm |
| November | -7.5 °C | 2.3 °C | 21.84 mm |
| December | -14.4 °C | -5.6 °C | 20.57 mm |
| Annual | -1.2 °C | 10.3 °C | 538.47 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 4a : -34.4°C to -31.7°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |