Longlac, Ontario climate data is summarized below. Average annual temperatures range from 24.2 °F (low) to 43.9 °F (high). Annual precipitation averages 23.6 Inches. Longlac is located in USDA Plant Hardiness Zone 2b. The growing season typically runs from the last frost around May 21 - May 31 through the first frost around Sep.11 - Sep. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -30.6 °F | -24.3 °F | 0 in. |
| February | -31 °F | -23.4 °F | 0 in. |
| March | -26.4 °F | -18.7 °F | 0 in. |
| April | -21.2 °F | -14.5 °F | 279.4 in. |
| May | -16.4 °F | -9.6 °F | 2387.6 in. |
| June | -12.9 °F | -6.3 °F | 3022.6 in. |
| July | -11.1 °F | -5.1 °F | 2971.8 in. |
| August | -11.5 °F | -5.4 °F | 2362.2 in. |
| September | -14.3 °F | -8.6 °F | 2387.6 in. |
| October | -17.3 °F | -13 °F | 1701.8 in. |
| November | -21.7 °F | -17.5 °F | 76.2 in. |
| December | -28 °F | -22.8 °F | 0 in. |
| Annual | 24.2 °F | 43.9 °F | 23.55 in. |
| Average First Frost Date | Sep.11 - Sep. 20 |
| Average Last Frost Date | May 21 - May 31 |
| Average Days With Frost | Over 180 Days |
| Plant Hardiness Zone | Zone 2b : -45°F to -40°F |
| Current Drought Conditions | Normal |