L'Islet-sur-Mer, Quebec climate data is summarized below. Average annual temperatures range from 35.8 °F (low) to 48 °F (high). Annual precipitation averages 24.5 Inches. L'Islet-sur-Mer is located in USDA Plant Hardiness Zone 5a. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Sep.11 - Sep. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -25.1 °F | -20.8 °F | 0 in. |
| February | -24.8 °F | -20.5 °F | 0 in. |
| March | -22.2 °F | -17.9 °F | 0 in. |
| April | -17.5 °F | -13.9 °F | 1016 in. |
| May | -13.9 °F | -9.7 °F | 1676.4 in. |
| June | -11.2 °F | -7.2 °F | 2032 in. |
| July | -9.4 °F | -5.5 °F | 2133.6 in. |
| August | -9.5 °F | -5.7 °F | 2336.8 in. |
| September | -11.7 °F | -8 °F | 2209.8 in. |
| October | -14.5 °F | -11.5 °F | 2590.8 in. |
| November | -17.5 °F | -14.8 °F | 1727.2 in. |
| December | -21.9 °F | -18.7 °F | 50.8 in. |
| Annual | 35.8 °F | 48 °F | 24.46 in. |
| Average First Frost Date | Sep.11 - Sep. 20 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5a : -20°F to -15°F |
| Current Drought Conditions | Normal |