St. Lewis, Newfoundland and Labrador climate data is summarized below. Average annual temperatures range from 30.8 °F (low) to 38.1 °F (high). Annual precipitation averages 23.5 Inches. St. Lewis is located in USDA Plant Hardiness Zone 3a. The growing season typically runs from the last frost around May 21 - May 31 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -24.1 °F | -20.9 °F | 406.4 in. |
| February | -24.1 °F | -20.8 °F | 381 in. |
| March | -22.4 °F | -19.6 °F | 558.8 in. |
| April | -19.8 °F | -17.9 °F | 711.2 in. |
| May | -17.8 °F | -16.1 °F | 1397 in. |
| June | -15.3 °F | -13.3 °F | 1524 in. |
| July | -12.7 °F | -10.5 °F | 1828.8 in. |
| August | -11.9 °F | -9.8 °F | 1473.2 in. |
| September | -13.6 °F | -11.7 °F | 1803.4 in. |
| October | -15.9 °F | -14.3 °F | 2209.8 in. |
| November | -18.7 °F | -16.8 °F | 1752.6 in. |
| December | -21.8 °F | -19.3 °F | 1092.2 in. |
| Annual | 30.8 °F | 38.1 °F | 23.47 in. |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 21 - May 31 |
| Average Days With Frost | Over 180 Days |
| Plant Hardiness Zone | Zone 3a : -40°F to -35°F |
| Current Drought Conditions | Normal |