Tecumseh, Michigan has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 3.5 °C (low) to 15.1 °C (high). Annual precipitation averages 903 Millimeters. Tecumseh 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 | -8.9 °C | -0.2 °C | 59.69 mm |
| February | -8.4 °C | 1.6 °C | 50.8 mm |
| March | -3.8 °C | 7.2 °C | 61.47 mm |
| April | 2.2 °C | 14.8 °C | 84.84 mm |
| May | 8.3 °C | 21.3 °C | 100.33 mm |
| June | 13.7 °C | 26.6 °C | 93.22 mm |
| July | 15.6 °C | 28.8 °C | 84.58 mm |
| August | 14.7 °C | 27.7 °C | 85.85 mm |
| September | 10.4 °C | 24.2 °C | 77.72 mm |
| October | 4.3 °C | 17 °C | 74.42 mm |
| November | -1.1 °C | 9.1 °C | 71.88 mm |
| December | -5.6 °C | 2.7 °C | 58.17 mm |
| Annual | 3.5 °C | 15.1 °C | 902.97 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 | Dfa - Humid Continental Hot Summers With Year Around Precipitation |