Mackinaw City, Michigan has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 2.2 °C (low) to 10.4 °C (high). Annual precipitation averages 807.5 Millimeters. Mackinaw City is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -10.6 °C | -3.5 °C | 48.01 mm |
| February | -11.2 °C | -2.7 °C | 34.04 mm |
| March | -7.1 °C | 1.8 °C | 43.18 mm |
| April | -0.6 °C | 7.9 °C | 68.58 mm |
| May | 5.4 °C | 14.8 °C | 74.93 mm |
| June | 11.3 °C | 20.5 °C | 72.9 mm |
| July | 14.8 °C | 23.8 °C | 72.39 mm |
| August | 14.6 °C | 23.6 °C | 77.47 mm |
| September | 10.9 °C | 19.7 °C | 87.12 mm |
| October | 4.8 °C | 12.6 °C | 106.17 mm |
| November | -0.4 °C | 5.9 °C | 65.28 mm |
| December | -5.7 °C | 0.3 °C | 57.4 mm |
| Annual | 2.2 °C | 10.4 °C | 807.47 mm |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5b : -26.1°C to -23.3°C |
| Plant Hardiness Zone - 2012 | Zone 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |