Kemptville, Ontario climate data is summarized below. Average annual temperatures range from 35.6 °F (low) to 53.9 °F (high). Annual precipitation averages 20 Inches. Kemptville is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -24.9 °F | -20 °F | 0 in. |
| February | -24.8 °F | -19.6 °F | 0 in. |
| March | -21.3 °F | -15.7 °F | 482.6 in. |
| April | -17 °F | -10.9 °F | 1168.4 in. |
| May | -13.5 °F | -6.7 °F | 1473.2 in. |
| June | -10.7 °F | -4.4 °F | 1727.2 in. |
| July | -9.3 °F | -3 °F | 2514.6 in. |
| August | -9.8 °F | -3.5 °F | 2260.6 in. |
| September | -12.4 °F | -5.9 °F | 1320.8 in. |
| October | -15.3 °F | -10 °F | 1066.8 in. |
| November | -18.6 °F | -13.9 °F | 660.4 in. |
| December | -22.4 °F | -18.5 °F | 254 in. |
| Annual | 35.6 °F | 53.9 °F | 20.03 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 5b : -15°F to -10°F |
| Current Drought Conditions | Normal |