Waterloo, Ontario climate data is summarized below. Average annual temperatures range from 36.6 °F (low) to 53.3 °F (high). Annual precipitation averages 29.1 Inches. Waterloo is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -23.2 °F | -19.3 °F | 177.8 in. |
| February | -24 °F | -19.5 °F | 101.6 in. |
| March | -20.7 °F | -15.5 °F | 914.4 in. |
| April | -17.2 °F | -11.4 °F | 1524 in. |
| May | -13.7 °F | -7.4 °F | 2235.2 in. |
| June | -11 °F | -4.9 °F | 2514.6 in. |
| July | -9.8 °F | -3.7 °F | 3251.2 in. |
| August | -10.1 °F | -4.2 °F | 3048 in. |
| September | -12.3 °F | -6.5 °F | 2057.4 in. |
| October | -15.1 °F | -10.2 °F | 1473.2 in. |
| November | -18.2 °F | -14 °F | 863.6 in. |
| December | -20.9 °F | -17.6 °F | 635 in. |
| Annual | 36.6 °F | 53.3 °F | 29.13 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 5b : -15°F to -10°F |
| Current Drought Conditions | Normal |