Smooth Rock Falls, Ontario climate data is summarized below. Average annual temperatures range from -3.8 °C (low) to 7.3 °C (high). Annual precipitation averages 660 Millimeters. 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 | -22.17 °C | -11.18 °C | 0 mm |
| February | -22.37 °C | -10.09 °C | 0 mm |
| March | -15.01 °C | -2.07 °C | 0 mm |
| April | -5.85 °C | 5.69 °C | 25 mm |
| May | 2.68 °C | 15.92 °C | 88 mm |
| June | 8.81 °C | 22.09 °C | 101 mm |
| July | 12.18 °C | 23.8 °C | 128 mm |
| August | 11.32 °C | 23 °C | 116 mm |
| September | 6.46 °C | 17.73 °C | 98 mm |
| October | 0.88 °C | 9.26 °C | 84 mm |
| November | -6.04 °C | 1.41 °C | 20 mm |
| December | -16.71 °C | -7.88 °C | 0 mm |
| Annual | -3.8 °C | 7.3 °C | 660 mm |
| 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 : -42.8°C to -40°C |
| Current Drought Conditions | Normal |