Orillia, Ontario climate data is summarized below. Average annual temperatures range from 2 °C (low) to 11.2 °C (high). Annual precipitation averages 508 Millimeters. Orillia 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 | -11.89 °C | -3.54 °C | 7 mm |
| February | -13.06 °C | -3.85 °C | 0 mm |
| March | -6.76 °C | 2.53 °C | 25 mm |
| April | 0.33 °C | 10.4 °C | 37 mm |
| May | 6.56 °C | 17.77 °C | 51 mm |
| June | 12.04 °C | 22.3 °C | 72 mm |
| July | 15.12 °C | 25.09 °C | 100 mm |
| August | 14.65 °C | 24.27 °C | 102 mm |
| September | 10.38 °C | 19.98 °C | 50 mm |
| October | 5.13 °C | 13.1 °C | 33 mm |
| November | -0.92 °C | 6.38 °C | 20 mm |
| December | -7.08 °C | -0.62 °C | 11 mm |
| Annual | 2 °C | 11.2 °C | 508 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Normal |