Penetanguishene, Ontario climate data is summarized below. Average annual temperatures range from 2.9 °C (low) to 11 °C (high). Annual precipitation averages 218 Millimeters. Penetanguishene 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. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -10.51 °C | -2.81 °C | 4 mm |
| February | -11.94 °C | -3.6 °C | 0 mm |
| March | -6.08 °C | 2.08 °C | 10 mm |
| April | 0.58 °C | 9.51 °C | 19 mm |
| May | 6.49 °C | 16.69 °C | 23 mm |
| June | 12.13 °C | 21.49 °C | 30 mm |
| July | 15.61 °C | 24.3 °C | 45 mm |
| August | 15.55 °C | 23.91 °C | 39 mm |
| September | 11.63 °C | 20.2 °C | 21 mm |
| October | 6.56 °C | 13.51 °C | 15 mm |
| November | 0.58 °C | 7.03 °C | 9 mm |
| December | -5.69 °C | 0.23 °C | 3 mm |
| Annual | 2.9 °C | 11 °C | 218 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| 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 |