Sandusky, Michigan has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 3 °C (low) to 13.3 °C (high). Annual precipitation averages 798.8 Millimeters. Sandusky is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -9.3 °C | -1.7 °C | 52.83 mm |
| February | -9.4 °C | -0.3 °C | 38.61 mm |
| March | -4.8 °C | 5.1 °C | 45.97 mm |
| April | 0.9 °C | 12.3 °C | 74.42 mm |
| May | 7.3 °C | 19.3 °C | 85.6 mm |
| June | 12.7 °C | 24.9 °C | 82.55 mm |
| July | 15.2 °C | 27.1 °C | 78.23 mm |
| August | 14.3 °C | 26.1 °C | 75.95 mm |
| September | 10.2 °C | 22.7 °C | 82.55 mm |
| October | 4.7 °C | 15.3 °C | 73.41 mm |
| November | -0.7 °C | 7.8 °C | 59.94 mm |
| December | -5.5 °C | 1.4 °C | 48.77 mm |
| Annual | 3 °C | 13.3 °C | 798.83 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6a : -23.3°C to -20.6°C |
| Plant Hardiness Zone - 2012 | Zone 6a : -23.3°C to -20.6°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |