Clinton, Ontario climate data is summarized below. Average annual temperatures range from 38 °F (low) to 54.7 °F (high). Annual precipitation averages 14.8 Inches. Clinton is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -22.5 °F | -18.9 °F | 25.4 in. |
| February | -23.7 °F | -19.2 °F | 0 in. |
| March | -20.5 °F | -15.4 °F | 584.2 in. |
| April | -16.8 °F | -10.9 °F | 609.6 in. |
| May | -13.4 °F | -7 °F | 1270 in. |
| June | -10.7 °F | -4.6 °F | 1473.2 in. |
| July | -9.5 °F | -3.3 °F | 1854.2 in. |
| August | -9.7 °F | -3.7 °F | 1498.6 in. |
| September | -11.9 °F | -5.8 °F | 1016 in. |
| October | -14.5 °F | -9.7 °F | 685.8 in. |
| November | -17.6 °F | -13.6 °F | 381 in. |
| December | -20.3 °F | -17.1 °F | 177.8 in. |
| Annual | 38 °F | 54.7 °F | 14.83 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6a : -10°F to -5°F |
| Current Drought Conditions | Normal |