Garrettsville, Ohio has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 3.9 °C (low) to 15.3 °C (high). Annual precipitation averages 1088.1 Millimeters. Garrettsville is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -7.9 °C | 1.1 °C | 79.5 mm |
| February | -7.4 °C | 2.7 °C | 62.99 mm |
| March | -3.2 °C | 7.8 °C | 84.84 mm |
| April | 2.5 °C | 15.3 °C | 100.08 mm |
| May | 8.3 °C | 21.3 °C | 103.89 mm |
| June | 13.3 °C | 25.9 °C | 105.66 mm |
| July | 15.4 °C | 28.1 °C | 109.98 mm |
| August | 14.5 °C | 27.3 °C | 89.92 mm |
| September | 10.9 °C | 23.7 °C | 99.82 mm |
| October | 4.8 °C | 16.8 °C | 90.42 mm |
| November | -0.1 °C | 9.8 °C | 80.26 mm |
| December | -4.4 °C | 3.8 °C | 80.77 mm |
| Annual | 3.9 °C | 15.3 °C | 1088.13 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6a : -23.3°C to -20.6°C |
| Plant Hardiness Zone - 2012 | Zone 6a : -23.3°C to -20.6°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |