Hearst, Ontario climate data is summarized below. Average annual temperatures range from -4.1 °C (low) to 7.2 °C (high). Annual precipitation averages 621 Millimeters. Hearst is located in USDA Plant Hardiness Zone 2a. The growing season typically runs from the last frost around Jun. 1 - Jun. 10 through the first frost around Sep.11 - Sep. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -22.39 °C | -11.29 °C | 0 mm |
| February | -22.52 °C | -9.93 °C | 0 mm |
| March | -15.17 °C | -1.93 °C | 0 mm |
| April | -6.17 °C | 5.75 °C | 18 mm |
| May | 2.33 °C | 15.54 °C | 85 mm |
| June | 8.54 °C | 21.84 °C | 105 mm |
| July | 12.12 °C | 23.77 °C | 113 mm |
| August | 11.14 °C | 23.02 °C | 103 mm |
| September | 6.33 °C | 17.44 °C | 105 mm |
| October | 0.75 °C | 8.95 °C | 74 mm |
| November | -6.5 °C | 0.98 °C | 18 mm |
| December | -17.18 °C | -8.3 °C | 0 mm |
| Annual | -4.1 °C | 7.2 °C | 621 mm |
| Average First Frost Date | Sep.11 - Sep. 20 |
| Average Last Frost Date | Jun. 1 - Jun. 10 |
| Average Days With Frost | Over 180 Days |
| Plant Hardiness Zone | Zone 2a : -45.6°C to -42.8°C |
| Current Drought Conditions | Normal |