Vassar, Michigan has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 37.3 °F (low) to 56.8 °F (high). Annual precipitation averages 33.2 Inches. Vassar 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 | 14.9 °F | 29.6 °F | 2.01 in. |
| February | 15.1 °F | 32.3 °F | 1.66 in. |
| March | 23.4 °F | 42.3 °F | 1.95 in. |
| April | 34.2 °F | 55.6 °F | 3.39 in. |
| May | 45.7 °F | 68.1 °F | 3.58 in. |
| June | 55.4 °F | 77.8 °F | 3.45 in. |
| July | 59.3 °F | 81.6 °F | 3.46 in. |
| August | 57.7 °F | 79.4 °F | 3.31 in. |
| September | 49.8 °F | 73.3 °F | 2.84 in. |
| October | 39.8 °F | 60.3 °F | 3.12 in. |
| November | 30.5 °F | 46.4 °F | 2.51 in. |
| December | 22.1 °F | 34.9 °F | 1.94 in. |
| Annual | 37.3 °F | 56.8 °F | 33.22 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 | Dfb - Humid Continental Mild Summer, Wet All Year |