Monroe, Michigan has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 5.4 °C (low) to 15.2 °C (high). Annual precipitation averages 902.2 Millimeters. Monroe 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. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -7.3 °C | 0.4 °C | 61.72 mm |
| February | -6.6 °C | 2 °C | 49.78 mm |
| March | -2.4 °C | 7.3 °C | 65.53 mm |
| April | 3.7 °C | 14.3 °C | 86.11 mm |
| May | 10.2 °C | 20.9 °C | 97.54 mm |
| June | 15.8 °C | 26.7 °C | 86.36 mm |
| July | 17.9 °C | 28.9 °C | 87.88 mm |
| August | 17 °C | 27.8 °C | 94.74 mm |
| September | 13.1 °C | 24.3 °C | 73.66 mm |
| October | 6.4 °C | 17 °C | 68.33 mm |
| November | 0.8 °C | 9.3 °C | 69.85 mm |
| December | -3.9 °C | 3.2 °C | 60.71 mm |
| Annual | 5.4 °C | 15.2 °C | 902.21 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 100-125 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 |