Grand Marais, Michigan has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 32.7 °F (low) to 51.4 °F (high). Annual precipitation averages 32.6 Inches. Grand Marais is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 11.0 °F | 25.0 °F | 2.41 in. |
| February | 10.7 °F | 27.4 °F | 1.66 in. |
| March | 17.2 °F | 36.5 °F | 1.92 in. |
| April | 27.9 °F | 48.2 °F | 2.7 in. |
| May | 38.4 °F | 61.4 °F | 2.56 in. |
| June | 47.9 °F | 71.2 °F | 2.95 in. |
| July | 52.9 °F | 75.4 °F | 2.93 in. |
| August | 54.2 °F | 76.0 °F | 2.28 in. |
| September | 48.8 °F | 68.8 °F | 3.55 in. |
| October | 37.7 °F | 54.9 °F | 4.17 in. |
| November | 27.9 °F | 41.3 °F | 2.9 in. |
| December | 17.8 °F | 31.1 °F | 2.56 in. |
| Annual | 32.7 °F | 51.4 °F | 32.59 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5b : -15°F to -10°F |
| Plant Hardiness Zone - 2012 | Zone 5b : -15°F to -10°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |