Gananoque, Ontario climate data is summarized below. Average annual temperatures range from 3.9 °C (low) to 12 °C (high). Annual precipitation averages 836 Millimeters. Gananoque 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. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -10.22 °C | -2.22 °C | 13 mm |
| February | -11.26 °C | -2.67 °C | 11 mm |
| March | -4.86 °C | 3.71 °C | 52 mm |
| April | 2.37 °C | 11.23 °C | 95 mm |
| May | 8.43 °C | 18.3 °C | 86 mm |
| June | 13.8 °C | 22.52 °C | 95 mm |
| July | 17.04 °C | 25.21 °C | 86 mm |
| August | 16.79 °C | 24.94 °C | 79 mm |
| September | 12.49 °C | 20.91 °C | 79 mm |
| October | 7.01 °C | 14.23 °C | 110 mm |
| November | 0.97 °C | 7.83 °C | 73 mm |
| December | -5.79 °C | 0.66 °C | 57 mm |
| Annual | 3.9 °C | 12 °C | 836 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6a : -23.3°C to -20.6°C |
| Current Drought Conditions | Normal |