Alma, Michigan has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 2.9 °C (low) to 13.9 °C (high). Annual precipitation averages 872.5 Millimeters. Alma 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 | -9.6 °C | -1.4 °C | 54.61 mm |
| February | -9.4 °C | -0.1 °C | 45.21 mm |
| March | -4.9 °C | 5.8 °C | 52.32 mm |
| April | 1.3 °C | 13.4 °C | 89.41 mm |
| May | 7.8 °C | 20.2 °C | 95.25 mm |
| June | 13.3 °C | 25.6 °C | 91.95 mm |
| July | 15.1 °C | 27.8 °C | 79.76 mm |
| August | 14.1 °C | 26.7 °C | 93.22 mm |
| September | 9.7 °C | 23 °C | 70.36 mm |
| October | 3.9 °C | 15.7 °C | 83.31 mm |
| November | -1.1 °C | 8.1 °C | 65.28 mm |
| December | -5.8 °C | 1.6 °C | 51.82 mm |
| Annual | 2.9 °C | 13.9 °C | 872.5 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 6a : -23.3°C to -20.6°C |
| Plant Hardiness Zone - 2012 | Zone 6a : -23.3°C to -20.6°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |