Delton, Michigan has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 4.1 °C (low) to 14.4 °C (high). Annual precipitation averages 1005.6 Millimeters. Delton 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 | -8.3 °C | -0.6 °C | 69.09 mm |
| February | -7.9 °C | 0.9 °C | 52.83 mm |
| March | -3.4 °C | 6.9 °C | 61.72 mm |
| April | 2.9 °C | 14.3 °C | 94.74 mm |
| May | 9.2 °C | 20.8 °C | 108.71 mm |
| June | 14.3 °C | 25.8 °C | 101.85 mm |
| July | 16.2 °C | 27.9 °C | 92.71 mm |
| August | 15.3 °C | 26.8 °C | 100.58 mm |
| September | 11.1 °C | 23.3 °C | 86.87 mm |
| October | 5.1 °C | 16.1 °C | 98.3 mm |
| November | -0.3 °C | 8.6 °C | 74.42 mm |
| December | -4.9 °C | 2.1 °C | 63.75 mm |
| Annual | 4.1 °C | 14.4 °C | 1005.57 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 |