Dunnville, Ontario climate data is summarized below. Average annual temperatures range from 40.6 °F (low) to 55.6 °F (high). Annual precipitation averages 36.1 Inches. Dunnville is located in USDA Plant Hardiness Zone 6b. 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 °F | -18.1 °F | 990.6 in. |
| February | -23 °F | -18.6 °F | 939.8 in. |
| March | -19.7 °F | -14.9 °F | 2108.2 in. |
| April | -16.5 °F | -11.3 °F | 2336.8 in. |
| May | -13.2 °F | -7.5 °F | 2489.2 in. |
| June | -9.9 °F | -4.8 °F | 2006.6 in. |
| July | -8.3 °F | -3.4 °F | 2133.6 in. |
| August | -8.5 °F | -3.6 °F | 1930.4 in. |
| September | -10.7 °F | -5.7 °F | 2082.8 in. |
| October | -13.7 °F | -9.3 °F | 2540 in. |
| November | -16.8 °F | -12.9 °F | 1752.6 in. |
| December | -19.5 °F | -16.2 °F | 1981.2 in. |
| Annual | 40.6 °F | 55.6 °F | 36.12 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 6b : -5°F to 0°F |
| Current Drought Conditions | Normal |