Smooth Rock Falls, Ontario climate data is summarized below. Average annual temperatures range from 25.1 °F (low) to 45.2 °F (high). Annual precipitation averages 26 Inches. Smooth Rock Falls is located in USDA Plant Hardiness Zone 2b. The growing season typically runs from the last frost around Jun. 1 - Jun. 10 through the first frost around Sep.11 - Sep. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -30.1 °F | -24 °F | 0 in. |
| February | -30.2 °F | -23.4 °F | 0 in. |
| March | -26.1 °F | -18.9 °F | 0 in. |
| April | -21 °F | -14.6 °F | 635 in. |
| May | -16.3 °F | -8.9 °F | 2235.2 in. |
| June | -12.9 °F | -5.5 °F | 2565.4 in. |
| July | -11 °F | -4.6 °F | 3251.2 in. |
| August | -11.5 °F | -5 °F | 2946.4 in. |
| September | -14.2 °F | -7.9 °F | 2489.2 in. |
| October | -17.3 °F | -12.6 °F | 2133.6 in. |
| November | -21.1 °F | -17 °F | 508 in. |
| December | -27.1 °F | -22.2 °F | 0 in. |
| Annual | 25.1 °F | 45.2 °F | 25.99 in. |
| Average First Frost Date | Sep.11 - Sep. 20 |
| Average Last Frost Date | Jun. 1 - Jun. 10 |
| Average Days With Frost | Over 180 Days |
| Plant Hardiness Zone | Zone 2b : -45°F to -40°F |
| Current Drought Conditions | Normal |