Clarence-Rockland, Ontario climate data is summarized below. Average annual temperatures range from 34.4 °F (low) to 53.1 °F (high). Annual precipitation averages 16.9 Inches. 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 | -25.8 °F | -20.6 °F | 0 in. |
| February | -25.7 °F | -20 °F | 0 in. |
| March | -22.2 °F | -16.3 °F | 406.4 in. |
| April | -17.3 °F | -11.2 °F | 863.6 in. |
| May | -13.6 °F | -6.8 °F | 1016 in. |
| June | -10.6 °F | -4.4 °F | 1676.4 in. |
| July | -9.3 °F | -3 °F | 2336.8 in. |
| August | -9.8 °F | -3.6 °F | 2006.6 in. |
| September | -12.6 °F | -6 °F | 1219.2 in. |
| October | -15.6 °F | -10.3 °F | 812.8 in. |
| November | -18.9 °F | -14.3 °F | 406.4 in. |
| December | -23 °F | -18.9 °F | 152.4 in. |
| Annual | 34.4 °F | 53.1 °F | 16.89 in. |
| 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 : -20°F to -15°F |
| Current Drought Conditions | Normal |