Copper Harbor, Michigan has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 35.2 °F (low) to 48.5 °F (high). Annual precipitation averages 32.1 Inches. Copper Harbor is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 14.2 °F | 24.3 °F | 2.51 in. |
| February | 13.5 °F | 25.8 °F | 1.87 in. |
| March | 20.1 °F | 33.9 °F | 1.89 in. |
| April | 30.5 °F | 44.1 °F | 2.57 in. |
| May | 40.1 °F | 57.0 °F | 2.8 in. |
| June | 47.9 °F | 65.9 °F | 2.69 in. |
| July | 55.7 °F | 71.6 °F | 2.43 in. |
| August | 57.7 °F | 72.0 °F | 2.5 in. |
| September | 51.5 °F | 65.1 °F | 2.93 in. |
| October | 40.3 °F | 51.9 °F | 3.67 in. |
| November | 29.7 °F | 40.1 °F | 3.03 in. |
| December | 20.8 °F | 30.3 °F | 3.2 in. |
| Annual | 35.2 °F | 48.5 °F | 32.09 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6a : -10°F to -5°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 |