Clarence-Rockland, Ontario climate data is summarized below. Average annual temperatures range from 1.3 °C (low) to 11.7 °C (high). Annual precipitation averages 429 Millimeters. Clarence-Rockland is located in USDA Plant Hardiness Zone 5a. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -14.45 °C | -5.02 °C | 0 mm |
| February | -14.29 °C | -4.08 °C | 0 mm |
| March | -7.96 °C | 2.66 °C | 16 mm |
| April | 0.83 °C | 11.84 °C | 34 mm |
| May | 7.6 °C | 19.84 °C | 40 mm |
| June | 12.88 °C | 24.09 °C | 66 mm |
| July | 15.28 °C | 26.62 °C | 92 mm |
| August | 14.29 °C | 25.61 °C | 79 mm |
| September | 9.41 °C | 21.14 °C | 48 mm |
| October | 3.94 °C | 13.51 °C | 32 mm |
| November | -2.04 °C | 6.27 °C | 16 mm |
| December | -9.48 °C | -2.01 °C | 6 mm |
| Annual | 1.3 °C | 11.7 °C | 429 mm |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5a : -28.9°C to -26.1°C |
| Current Drought Conditions | Normal |