Marathon, 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 17.6 °C (high). Annual precipitation averages 1163.1 Millimeters. Marathon is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -5.6 °C | 3.6 °C | 81.79 mm |
| February | -4.2 °C | 5.9 °C | 75.44 mm |
| March | -0.1 °C | 11.3 °C | 107.44 mm |
| April | 5.6 °C | 18.1 °C | 119.38 mm |
| May | 11.6 °C | 23.1 °C | 123.19 mm |
| June | 16.3 °C | 27.7 °C | 121.16 mm |
| July | 18.1 °C | 29.4 °C | 115.82 mm |
| August | 17.1 °C | 28.9 °C | 95 mm |
| September | 13.1 °C | 25.8 °C | 78.23 mm |
| October | 6.7 °C | 19.3 °C | 74.93 mm |
| November | 1.2 °C | 11.9 °C | 82.04 mm |
| December | -2.7 °C | 5.9 °C | 88.65 mm |
| Annual | 6.4 °C | 17.6 °C | 1163.07 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| 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 |