Waterdown, Ontario climate data is summarized below. Average annual temperatures range from 40.3 °F (low) to 55.9 °F (high). Annual precipitation averages 37.3 Inches. Waterdown is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Nov. 1 - Nov. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -22 °F | -18.2 °F | 660.4 in. |
| February | -22.7 °F | -18.5 °F | 863.6 in. |
| March | -19.5 °F | -14.8 °F | 2032 in. |
| April | -16.3 °F | -11.1 °F | 2463.8 in. |
| May | -12.9 °F | -7.2 °F | 2540 in. |
| June | -9.9 °F | -4.4 °F | 2489.2 in. |
| July | -8.4 °F | -2.7 °F | 2565.4 in. |
| August | -8.6 °F | -3.2 °F | 2590.8 in. |
| September | -10.9 °F | -5.6 °F | 2108.2 in. |
| October | -14.1 °F | -9.4 °F | 2235.2 in. |
| November | -17.2 °F | -13.1 °F | 1778 in. |
| December | -19.9 °F | -16.6 °F | 1727.2 in. |
| Annual | 40.3 °F | 55.9 °F | 37.3 in. |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 6a : -10°F to -5°F |
| Current Drought Conditions | Normal |