West Branch, Michigan has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 33.1 °F (low) to 55.5 °F (high). Annual precipitation averages 33.3 Inches. West Branch is located in USDA Plant Hardiness Zone 5a. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 10.6 °F | 27.8 °F | 2.01 in. |
| February | 10.1 °F | 30.8 °F | 1.64 in. |
| March | 18.0 °F | 41.1 °F | 1.83 in. |
| April | 30.0 °F | 54.2 °F | 3.33 in. |
| May | 41.6 °F | 67.4 °F | 3.47 in. |
| June | 51.2 °F | 77.0 °F | 3.52 in. |
| July | 55.3 °F | 80.9 °F | 3.41 in. |
| August | 53.7 °F | 79.2 °F | 3.39 in. |
| September | 45.8 °F | 72.0 °F | 2.69 in. |
| October | 35.5 °F | 58.2 °F | 3.33 in. |
| November | 26.8 °F | 44.1 °F | 2.53 in. |
| December | 18.3 °F | 33.2 °F | 2.11 in. |
| Annual | 33.1 °F | 55.5 °F | 33.26 in. |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 11 - May 20 |
| 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 |