Thompsonville, Michigan has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 2.4 °C (low) to 12.8 °C (high). Annual precipitation averages 889.3 Millimeters. Thompsonville 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 | -2 °C | 55.12 mm |
| February | -9.4 °C | -0.6 °C | 38.1 mm |
| March | -5.8 °C | 4.8 °C | 52.07 mm |
| April | 0.1 °C | 11.8 °C | 76.96 mm |
| May | 6.2 °C | 19.1 °C | 81.79 mm |
| June | 11.7 °C | 24.4 °C | 81.28 mm |
| July | 14.3 °C | 26.6 °C | 77.47 mm |
| August | 13.7 °C | 25.7 °C | 79.25 mm |
| September | 10 °C | 21.9 °C | 92.96 mm |
| October | 4.2 °C | 14.4 °C | 112.27 mm |
| November | -0.9 °C | 6.8 °C | 79.76 mm |
| December | -5.6 °C | 0.9 °C | 62.23 mm |
| Annual | 2.4 °C | 12.8 °C | 889.26 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 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |