Stouffville, Ontario climate data is summarized below. Average annual temperatures range from 3 °C (low) to 12.6 °C (high). Annual precipitation averages 904 Millimeters. Stouffville 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. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -9.95 °C | -2.09 °C | 17 mm |
| February | -11.04 °C | -2.46 °C | 11 mm |
| March | -5.62 °C | 4.13 °C | 59 mm |
| April | 1.61 °C | 12.02 °C | 93 mm |
| May | 8.03 °C | 19.52 °C | 102 mm |
| June | 13.02 °C | 24.15 °C | 112 mm |
| July | 15.53 °C | 26.76 °C | 118 mm |
| August | 14.88 °C | 25.84 °C | 120 mm |
| September | 10.38 °C | 21.24 °C | 82 mm |
| October | 5.19 °C | 13.89 °C | 81 mm |
| November | -0.64 °C | 7.29 °C | 61 mm |
| December | -5.81 °C | 0.66 °C | 48 mm |
| Annual | 3 °C | 12.6 °C | 904 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| 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 |