Rocky Harbour, Newfoundland and Labrador climate data is summarized below. Average annual temperatures range from 0.2 °C (low) to 5.5 °C (high). Annual precipitation averages 834 Millimeters. Rocky Harbour is located in USDA Plant Hardiness Zone 4b. The growing season typically runs from the last frost around Jun. 1 - Jun. 10 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -9.95 °C | -4.48 °C | 15 mm |
| February | -10.43 °C | -4.88 °C | 3 mm |
| March | -8.86 °C | -3.22 °C | 24 mm |
| April | -3.48 °C | 1.26 °C | 47 mm |
| May | 1.15 °C | 7.15 °C | 78 mm |
| June | 6.34 °C | 12.49 °C | 68 mm |
| July | 10.96 °C | 17.22 °C | 91 mm |
| August | 11.78 °C | 17.66 °C | 115 mm |
| September | 8.28 °C | 13.52 °C | 126 mm |
| October | 3.82 °C | 7.96 °C | 115 mm |
| November | -1.07 °C | 3.05 °C | 96 mm |
| December | -6.06 °C | -1.56 °C | 56 mm |
| Annual | 0.2 °C | 5.5 °C | 834 mm |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | Jun. 1 - Jun. 10 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 4b : -31.7°C to -28.9°C |
| Current Drought Conditions | Normal |