Corunna, Ontario climate data is summarized below. Average annual temperatures range from 38.8 °F (low) to 57 °F (high). Annual precipitation averages 8.4 Inches. 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 | -22.5 °F | -18.3 °F | 152.4 in. |
| February | -22.9 °F | -18.4 °F | 0 in. |
| March | -19.6 °F | -14.2 °F | 304.8 in. |
| April | -16.7 °F | -10.2 °F | 584.2 in. |
| May | -13.4 °F | -6.5 °F | 787.4 in. |
| June | -10.5 °F | -3.6 °F | 660.4 in. |
| July | -9.1 °F | -2.5 °F | 736.6 in. |
| August | -9.3 °F | -2.9 °F | 762 in. |
| September | -11.7 °F | -5.3 °F | 558.8 in. |
| October | -14.5 °F | -9.1 °F | 355.6 in. |
| November | -17.7 °F | -13 °F | 330.2 in. |
| December | -20.2 °F | -16.6 °F | 177.8 in. |
| Annual | 38.8 °F | 57 °F | 8.39 in. |
| 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 : 0°F to 5°F |
| Current Drought Conditions | Normal |