Tecumseh, Ontario climate data is summarized below. Average annual temperatures range from 5.9 °C (low) to 14.3 °C (high). Annual precipitation averages 584 Millimeters. Tecumseh is located in USDA Plant Hardiness Zone 7a. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -7.21 °C | -0.73 °C | 18 mm |
| February | -7.83 °C | -0.76 °C | 9 mm |
| March | -1.64 °C | 7.03 °C | 39 mm |
| April | 4.04 °C | 14.04 °C | 56 mm |
| May | 10.5 °C | 20.66 °C | 69 mm |
| June | 16.27 °C | 25.84 °C | 79 mm |
| July | 18.7 °C | 27.98 °C | 73 mm |
| August | 18.13 °C | 27.03 °C | 63 mm |
| September | 13.78 °C | 22.77 °C | 65 mm |
| October | 7.91 °C | 16.18 °C | 41 mm |
| November | 1.66 °C | 8.95 °C | 43 mm |
| December | -3.13 °C | 2.46 °C | 29 mm |
| Annual | 5.9 °C | 14.3 °C | 584 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 7a : -17.8°C to -15°C |
| Current Drought Conditions | Normal |