Kemptville, Ontario climate data is summarized below. Average annual temperatures range from 2 °C (low) to 12.2 °C (high). Annual precipitation averages 509 Millimeters. 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 | -12.77 °C | -4 °C | 0 mm |
| February | -12.66 °C | -3.36 °C | 0 mm |
| March | -6.29 °C | 3.67 °C | 19 mm |
| April | 1.34 °C | 12.38 °C | 46 mm |
| May | 7.76 °C | 20.03 °C | 58 mm |
| June | 12.82 °C | 24.1 °C | 68 mm |
| July | 15.21 °C | 26.67 °C | 99 mm |
| August | 14.29 °C | 25.74 °C | 89 mm |
| September | 9.68 °C | 21.33 °C | 52 mm |
| October | 4.38 °C | 13.97 °C | 42 mm |
| November | -1.48 °C | 6.91 °C | 26 mm |
| December | -8.29 °C | -1.22 °C | 10 mm |
| Annual | 2 °C | 12.2 °C | 509 mm |
| 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 : -26.1°C to -23.3°C |
| Current Drought Conditions | Normal |