Plymouth, Michigan has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 4.4 °C (low) to 15.3 °C (high). Annual precipitation averages 867.2 Millimeters. Plymouth is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -8 °C | 0.1 °C | 60.45 mm |
| February | -7.6 °C | 1.8 °C | 49.28 mm |
| March | -3.1 °C | 7.7 °C | 59.44 mm |
| April | 2.7 °C | 14.9 °C | 78.99 mm |
| May | 8.9 °C | 21.8 °C | 94.74 mm |
| June | 14.5 °C | 26.8 °C | 88.65 mm |
| July | 16.8 °C | 29.1 °C | 82.3 mm |
| August | 16.1 °C | 28.1 °C | 82.04 mm |
| September | 11.8 °C | 24.4 °C | 78.23 mm |
| October | 5.5 °C | 17.1 °C | 71.37 mm |
| November | 0.1 °C | 9.4 °C | 64.52 mm |
| December | -4.4 °C | 2.9 °C | 57.15 mm |
| Annual | 4.4 °C | 15.3 °C | 867.16 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6b : -20.6°C to -17.8°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 |