Corunna, Ontario climate data is summarized below. Average annual temperatures range from 3.8 °C (low) to 13.9 °C (high). Annual precipitation averages 213 Millimeters. Corunna 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 | -8.5 °C | -0.98 °C | 6 mm |
| February | -9.29 °C | -1.11 °C | 0 mm |
| March | -3.26 °C | 6.48 °C | 12 mm |
| April | 1.91 °C | 13.57 °C | 23 mm |
| May | 7.96 °C | 20.36 °C | 31 mm |
| June | 13.11 °C | 25.45 °C | 26 mm |
| July | 15.65 °C | 27.57 °C | 29 mm |
| August | 15.2 °C | 26.74 °C | 30 mm |
| September | 10.88 °C | 22.41 °C | 22 mm |
| October | 5.9 °C | 15.71 °C | 14 mm |
| November | 0.2 °C | 8.63 °C | 13 mm |
| December | -4.29 °C | 2.08 °C | 7 mm |
| Annual | 3.8 °C | 13.9 °C | 213 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 |