Roscommon, Michigan has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 32.2 °F (low) to 54.6 °F (high). Annual precipitation averages 34 Inches. Roscommon is located in USDA Plant Hardiness Zone 5a. The growing season typically runs from the last frost around May 21 - May 31 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 9.7 °F | 26.9 °F | 2.26 in. |
| February | 8.9 °F | 30.0 °F | 1.62 in. |
| March | 16.5 °F | 40.2 °F | 1.94 in. |
| April | 28.7 °F | 53.2 °F | 3.21 in. |
| May | 40.8 °F | 66.7 °F | 3.47 in. |
| June | 50.3 °F | 76.5 °F | 3.53 in. |
| July | 54.4 °F | 80.4 °F | 3.08 in. |
| August | 52.6 °F | 78.5 °F | 3.27 in. |
| September | 44.8 °F | 71.0 °F | 3.07 in. |
| October | 35.1 °F | 56.9 °F | 3.62 in. |
| November | 26.2 °F | 43.1 °F | 2.71 in. |
| December | 17.8 °F | 32.0 °F | 2.22 in. |
| Annual | 32.2 °F | 54.6 °F | 34 in. |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 21 - May 31 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5a : -20°F to -15°F |
| Plant Hardiness Zone - 2012 | Zone 4b : -25°F to -20°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |