West Branch, Michigan has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 0.6 °C (low) to 13.1 °C (high). Annual precipitation averages 844.8 Millimeters. 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 | -11.9 °C | -2.3 °C | 51.05 mm |
| February | -12.2 °C | -0.7 °C | 41.66 mm |
| March | -7.8 °C | 5.1 °C | 46.48 mm |
| April | -1.1 °C | 12.3 °C | 84.58 mm |
| May | 5.3 °C | 19.7 °C | 88.14 mm |
| June | 10.7 °C | 25 °C | 89.41 mm |
| July | 12.9 °C | 27.2 °C | 86.61 mm |
| August | 12.1 °C | 26.2 °C | 86.11 mm |
| September | 7.7 °C | 22.2 °C | 68.33 mm |
| October | 1.9 °C | 14.6 °C | 84.58 mm |
| November | -2.9 °C | 6.7 °C | 64.26 mm |
| December | -7.6 °C | 0.7 °C | 53.59 mm |
| Annual | 0.6 °C | 13.1 °C | 844.8 mm |
| 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 : -28.9°C to -26.1°C |
| Plant Hardiness Zone - 2012 | Zone 5a : -28.9°C to -26.1°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |