Buchanan, Michigan has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 4.9 °C (low) to 15 °C (high). Annual precipitation averages 1048.3 Millimeters. Buchanan 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. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -7.7 °C | -0.1 °C | 79.25 mm |
| February | -6.6 °C | 1.7 °C | 62.23 mm |
| March | -2.2 °C | 7.7 °C | 63.25 mm |
| April | 3.6 °C | 14.8 °C | 89.92 mm |
| May | 9.6 °C | 21.1 °C | 100.33 mm |
| June | 14.6 °C | 26.2 °C | 105.41 mm |
| July | 16.8 °C | 28.3 °C | 97.03 mm |
| August | 16.2 °C | 27.3 °C | 114.05 mm |
| September | 12.1 °C | 23.9 °C | 87.12 mm |
| October | 5.9 °C | 16.9 °C | 105.92 mm |
| November | 0.4 °C | 9 °C | 76.96 mm |
| December | -4.3 °C | 2.7 °C | 66.8 mm |
| Annual | 4.9 °C | 15 °C | 1048.27 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6a : -23.3°C to -20.6°C |
| Plant Hardiness Zone - 2012 | Zone 6a : -23.3°C to -20.6°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |