Romeo, Michigan has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 3.9 °C (low) to 14.3 °C (high). Annual precipitation averages 876.6 Millimeters. Romeo 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 | -8.8 °C | -0.7 °C | 65.53 mm |
| February | -8.4 °C | 1 °C | 51.31 mm |
| March | -3.9 °C | 6.4 °C | 58.93 mm |
| April | 2.1 °C | 13.6 °C | 84.33 mm |
| May | 8.4 °C | 20.4 °C | 90.68 mm |
| June | 13.9 °C | 25.8 °C | 80.01 mm |
| July | 16.2 °C | 28.1 °C | 95.5 mm |
| August | 15.5 °C | 27.1 °C | 81.03 mm |
| September | 11.4 °C | 23.4 °C | 71.63 mm |
| October | 5.2 °C | 15.8 °C | 71.37 mm |
| November | -0.3 °C | 8.7 °C | 66.04 mm |
| December | -5.1 °C | 2.1 °C | 60.2 mm |
| Annual | 3.9 °C | 14.3 °C | 876.56 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 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |