Marathon, Ohio has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 43.6 °F (low) to 63.7 °F (high). Annual precipitation averages 45.8 Inches. 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 | 22.0 °F | 38.5 °F | 3.22 in. |
| February | 24.4 °F | 42.7 °F | 2.97 in. |
| March | 31.9 °F | 52.3 °F | 4.23 in. |
| April | 42.0 °F | 64.5 °F | 4.7 in. |
| May | 52.8 °F | 73.6 °F | 4.85 in. |
| June | 61.4 °F | 81.9 °F | 4.77 in. |
| July | 64.5 °F | 85.0 °F | 4.56 in. |
| August | 62.7 °F | 84.1 °F | 3.74 in. |
| September | 55.5 °F | 78.5 °F | 3.08 in. |
| October | 44.1 °F | 66.7 °F | 2.95 in. |
| November | 34.1 °F | 53.4 °F | 3.23 in. |
| December | 27.2 °F | 42.6 °F | 3.49 in. |
| Annual | 43.6 °F | 63.7 °F | 45.79 in. |
| 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 : -5°F to 0°F |
| Plant Hardiness Zone - 2012 | Zone 6a : -10°F to -5°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |