Alanson, Michigan has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 33.8 °F (low) to 53.8 °F (high). Annual precipitation averages 33.8 Inches. Alanson 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 | 11.5 °F | 27.1 °F | 2.36 in. |
| February | 9.9 °F | 29.2 °F | 1.55 in. |
| March | 17.3 °F | 38.8 °F | 1.82 in. |
| April | 29.8 °F | 51.0 °F | 2.87 in. |
| May | 41.3 °F | 65.1 °F | 2.93 in. |
| June | 51.1 °F | 74.7 °F | 2.88 in. |
| July | 55.9 °F | 78.7 °F | 2.79 in. |
| August | 54.6 °F | 77.6 °F | 3.15 in. |
| September | 47.5 °F | 70.4 °F | 3.52 in. |
| October | 37.7 °F | 56.7 °F | 4.25 in. |
| November | 29.1 °F | 43.7 °F | 3.04 in. |
| December | 20.2 °F | 33.0 °F | 2.66 in. |
| Annual | 33.8 °F | 53.8 °F | 33.82 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 5a : -20°F to -15°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |