Mattawan, Michigan has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 39.5 °F (low) to 57.9 °F (high). Annual precipitation averages 39.5 Inches. Mattawan 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 | 17.2 °F | 30.9 °F | 2.85 in. |
| February | 18.4 °F | 33.8 °F | 2.08 in. |
| March | 26.1 °F | 44.5 °F | 2.37 in. |
| April | 37.2 °F | 57.6 °F | 3.49 in. |
| May | 48.6 °F | 69.0 °F | 4.21 in. |
| June | 57.6 °F | 78.2 °F | 3.9 in. |
| July | 61.3 °F | 82.3 °F | 3.64 in. |
| August | 59.6 °F | 80.5 °F | 3.96 in. |
| September | 52.1 °F | 74.2 °F | 3.48 in. |
| October | 40.8 °F | 60.9 °F | 4.06 in. |
| November | 31.7 °F | 47.5 °F | 2.93 in. |
| December | 23.2 °F | 35.8 °F | 2.57 in. |
| Annual | 39.5 °F | 57.9 °F | 39.54 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 |