Monroe, Michigan has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 41.7 °F (low) to 59.3 °F (high). Annual precipitation averages 35.5 Inches. 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 | 18.8 °F | 32.8 °F | 2.43 in. |
| February | 20.1 °F | 35.6 °F | 1.96 in. |
| March | 27.7 °F | 45.1 °F | 2.58 in. |
| April | 38.6 °F | 57.7 °F | 3.39 in. |
| May | 50.3 °F | 69.7 °F | 3.84 in. |
| June | 60.4 °F | 80.1 °F | 3.4 in. |
| July | 64.2 °F | 84.0 °F | 3.46 in. |
| August | 62.6 °F | 82.1 °F | 3.73 in. |
| September | 55.6 °F | 75.8 °F | 2.9 in. |
| October | 43.6 °F | 62.6 °F | 2.69 in. |
| November | 33.5 °F | 48.8 °F | 2.75 in. |
| December | 25.0 °F | 37.7 °F | 2.39 in. |
| Annual | 41.7 °F | 59.3 °F | 35.52 in. |
| 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 : -5°F to 0°F |
| Plant Hardiness Zone - 2012 | Zone 6a : -10°F to -5°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |