Royal Oak, 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 865.6 Millimeters. Royal Oak 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 | -7.6 °C | 0.1 °C | 60.2 mm |
| February | -7 °C | 1.8 °C | 49.78 mm |
| March | -2.9 °C | 7.3 °C | 59.44 mm |
| April | 2.9 °C | 14.4 °C | 79.76 mm |
| May | 9.1 °C | 21.1 °C | 95.76 mm |
| June | 14.8 °C | 26.4 °C | 81.53 mm |
| July | 17.2 °C | 28.7 °C | 85.09 mm |
| August | 16.7 °C | 27.8 °C | 83.06 mm |
| September | 12.6 °C | 24.1 °C | 78.49 mm |
| October | 6.1 °C | 16.7 °C | 71.88 mm |
| November | 0.9 °C | 9.3 °C | 62.74 mm |
| December | -3.9 °C | 2.8 °C | 57.91 mm |
| Annual | 4.9 °C | 15 °C | 865.64 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 |