L'Islet-sur-Mer, Quebec climate data is summarized below. Average annual temperatures range from 2.1 °C (low) to 8.9 °C (high). Annual precipitation averages 621 Millimeters. 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 | -13.23 °C | -5.5 °C | 0 mm |
| February | -12.63 °C | -4.85 °C | 0 mm |
| March | -7.96 °C | -0.2 °C | 0 mm |
| April | 0.47 °C | 6.96 °C | 40 mm |
| May | 6.92 °C | 14.46 °C | 66 mm |
| June | 11.86 °C | 19.04 °C | 80 mm |
| July | 15.06 °C | 22.03 °C | 84 mm |
| August | 14.94 °C | 21.69 °C | 92 mm |
| September | 10.96 °C | 17.68 °C | 87 mm |
| October | 5.91 °C | 11.37 °C | 102 mm |
| November | 0.46 °C | 5.38 °C | 68 mm |
| December | -7.4 °C | -1.74 °C | 2 mm |
| Annual | 2.1 °C | 8.9 °C | 621 mm |
| 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 : -28.9°C to -26.1°C |
| Current Drought Conditions | Normal |