Southern Harbour, Newfoundland and Labrador climate data is summarized below. Average annual temperatures range from 37.1 °F (low) to 46.1 °F (high). Annual precipitation averages 40.4 Inches. Southern Harbour is located in USDA Plant Hardiness Zone . 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 | -21.2 °F | -18 °F | 1727.2 in. |
| February | -21.6 °F | -18.6 °F | 1651 in. |
| March | -20.6 °F | -17.9 °F | 1549.4 in. |
| April | -18.3 °F | -15.8 °F | 1828.8 in. |
| May | -16.1 °F | -13.3 °F | 2057.4 in. |
| June | -13.7 °F | -10.8 °F | 1828.8 in. |
| July | -11 °F | -8 °F | 1981.2 in. |
| August | -10.2 °F | -7.3 °F | 2159 in. |
| September | -11.9 °F | -9 °F | 2743.2 in. |
| October | -14.2 °F | -11.7 °F | 3022.6 in. |
| November | -16.6 °F | -14.1 °F | 2921 in. |
| December | -19.2 °F | -16.5 °F | 2565.4 in. |
| Annual | 37.1 °F | 46.1 °F | 40.36 in. |
| Average First Frost Date | Sep.11 - Sep. 20 |
| Average Last Frost Date | Jun. 1 - Jun. 10 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | |
| Current Drought Conditions | Normal |