Westlake, Ohio has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 6.4 °C (low) to 15.3 °C (high). Annual precipitation averages 1048 Millimeters. Westlake is located in USDA Plant Hardiness Zone 7a. 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 | -5.9 °C | 1.6 °C | 74.93 mm |
| February | -5.3 °C | 2.8 °C | 57.66 mm |
| March | -1.7 °C | 7.3 °C | 81.28 mm |
| April | 4.6 °C | 14.8 °C | 98.81 mm |
| May | 10.8 °C | 20.8 °C | 97.28 mm |
| June | 16.2 °C | 25.8 °C | 99.82 mm |
| July | 18.6 °C | 27.8 °C | 94.49 mm |
| August | 17.9 °C | 27.1 °C | 95.5 mm |
| September | 14.2 °C | 23.7 °C | 98.81 mm |
| October | 8.1 °C | 17.2 °C | 92.2 mm |
| November | 2.4 °C | 10.3 °C | 80.52 mm |
| December | -2.6 °C | 4.3 °C | 76.71 mm |
| Annual | 6.4 °C | 15.3 °C | 1048.01 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 7a : -17.8°C to -15°C |
| Plant Hardiness Zone - 2012 | Zone 6b : -20.6°C to -17.8°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |