Haileybury, Ontario climate data is summarized below. Average annual temperatures range from -1.3 °C (low) to 8.3 °C (high). Annual precipitation averages 654 Millimeters. Haileybury is located in USDA Plant Hardiness Zone 3b. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -18.32 °C | -8.75 °C | 0 mm |
| February | -18.3 °C | -8.12 °C | 0 mm |
| March | -11.21 °C | -0.92 °C | 6 mm |
| April | -2.83 °C | 7.08 °C | 50 mm |
| May | 4.7 °C | 16.46 °C | 67 mm |
| June | 10.25 °C | 21.08 °C | 74 mm |
| July | 12.98 °C | 23.18 °C | 103 mm |
| August | 12.47 °C | 22.33 °C | 112 mm |
| September | 7.91 °C | 17.84 °C | 89 mm |
| October | 2.54 °C | 10.46 °C | 110 mm |
| November | -3.43 °C | 3.37 °C | 43 mm |
| December | -12.93 °C | -5.13 °C | 0 mm |
| Annual | -1.3 °C | 8.3 °C | 654 mm |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 3b : -37.2°C to -34.4°C |
| Current Drought Conditions | Normal |