Amasa, Michigan has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 28.4 °F (low) to 51 °F (high). Annual precipitation averages 29.1 Inches. Amasa is located in USDA Plant Hardiness Zone 4a. The growing season typically runs from the last frost around Jun. 1 - Jun. 10 through the first frost around Sep.1 - Sep. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 2.6 °F | 21.7 °F | 1.33 in. |
| February | 2.8 °F | 25.9 °F | 1.06 in. |
| March | 12.0 °F | 37.1 °F | 1.43 in. |
| April | 25.6 °F | 49.5 °F | 2.53 in. |
| May | 38.4 °F | 64.4 °F | 3.03 in. |
| June | 48.3 °F | 73.7 °F | 3.29 in. |
| July | 52.4 °F | 77.8 °F | 3.39 in. |
| August | 50.3 °F | 75.5 °F | 3.0 in. |
| September | 43.6 °F | 67.7 °F | 3.51 in. |
| October | 32.7 °F | 53.2 °F | 3.17 in. |
| November | 22.2 °F | 38.4 °F | 1.82 in. |
| December | 10.3 °F | 26.5 °F | 1.54 in. |
| Annual | 28.4 °F | 51 °F | 29.1 in. |
| Average First Frost Date | Sep.1 - Sep. 10 |
| Average Last Frost Date | Jun. 1 - Jun. 10 |
| Average Days With Frost | Over 180 Days |
| Plant Hardiness Zone | Zone 4a : -30°F to -25°F |
| Plant Hardiness Zone - 2012 | Zone 4a : -30°F to -25°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |