Holly, Michigan has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 38.1 °F (low) to 56.8 °F (high). Annual precipitation averages 33.3 Inches. Holly 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 | 15.2 °F | 29.8 °F | 2.24 in. |
| February | 15.8 °F | 32.7 °F | 1.75 in. |
| March | 24.0 °F | 42.9 °F | 2.04 in. |
| April | 35.5 °F | 55.7 °F | 3.13 in. |
| May | 46.8 °F | 67.9 °F | 3.76 in. |
| June | 56.3 °F | 77.2 °F | 3.41 in. |
| July | 59.9 °F | 81.1 °F | 3.45 in. |
| August | 58.9 °F | 79.3 °F | 3.19 in. |
| September | 51.6 °F | 73.1 °F | 3.03 in. |
| October | 40.5 °F | 59.8 °F | 2.84 in. |
| November | 30.8 °F | 46.7 °F | 2.39 in. |
| December | 22.0 °F | 35.0 °F | 2.11 in. |
| Annual | 38.1 °F | 56.8 °F | 33.34 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 6a : -10°F to -5°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |