Harbour Breton, Newfoundland and Labrador climate data is summarized below. Average annual temperatures range from 2.5 °C (low) to 8.2 °C (high). Annual precipitation averages 1263 Millimeters. Harbour Breton is located in USDA Plant Hardiness Zone . The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -6.59 °C | -1.02 °C | 81 mm |
| February | -7.63 °C | -1.85 °C | 76 mm |
| March | -5.56 °C | -0.24 °C | 69 mm |
| April | -1.31 °C | 4.25 °C | 90 mm |
| May | 3.08 °C | 9.52 °C | 96 mm |
| June | 7.5 °C | 13.7 °C | 101 mm |
| July | 12.23 °C | 18.16 °C | 109 mm |
| August | 13.46 °C | 19.7 °C | 109 mm |
| September | 10.15 °C | 16.46 °C | 125 mm |
| October | 5.92 °C | 11.05 °C | 149 mm |
| November | 1.6 °C | 6.42 °C | 140 mm |
| December | -2.87 °C | 2.08 °C | 118 mm |
| Annual | 2.5 °C | 8.2 °C | 1263 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | |
| Current Drought Conditions | Normal |