St. Joseph's, Newfoundland and Labrador climate data is summarized below. Average annual temperatures range from 36.1 °F (low) to 47.7 °F (high). Annual precipitation averages 46.3 Inches. St. Joseph's is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around May 21 - May 31 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -21.2 °F | -17.8 °F | 2082.8 in. |
| February | -21.8 °F | -18.4 °F | 2108.2 in. |
| March | -20.8 °F | -17.7 °F | 2032 in. |
| April | -18.7 °F | -15.2 °F | 2413 in. |
| May | -16.4 °F | -12.3 °F | 2286 in. |
| June | -14.1 °F | -9.9 °F | 2057.4 in. |
| July | -11.3 °F | -7.1 °F | 2286 in. |
| August | -10.6 °F | -6.6 °F | 2184.4 in. |
| September | -12.4 °F | -8.4 °F | 2768.6 in. |
| October | -14.5 °F | -11.4 °F | 3352.8 in. |
| November | -16.9 °F | -13.9 °F | 3302 in. |
| December | -19.3 °F | -16.4 °F | 2971.8 in. |
| Annual | 36.1 °F | 47.7 °F | 46.27 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 21 - May 31 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5b : -15°F to -10°F |
| Current Drought Conditions | Normal |