Old Fort, Ohio has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 5 °C (low) to 15.7 °C (high). Annual precipitation averages 952 Millimeters. Old Fort 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 | -7.6 °C | 0.8 °C | 62.99 mm |
| February | -6.6 °C | 2.4 °C | 55.12 mm |
| March | -2.2 °C | 8 °C | 66.29 mm |
| April | 3.4 °C | 15.4 °C | 94.23 mm |
| May | 9.9 °C | 21.8 °C | 97.79 mm |
| June | 15.4 °C | 27.1 °C | 99.57 mm |
| July | 17.2 °C | 29.1 °C | 98.55 mm |
| August | 16.1 °C | 27.9 °C | 86.87 mm |
| September | 12 °C | 24.7 °C | 82.8 mm |
| October | 5.8 °C | 17.8 °C | 72.64 mm |
| November | 0.4 °C | 9.9 °C | 70.87 mm |
| December | -4.3 °C | 3.6 °C | 64.26 mm |
| Annual | 5 °C | 15.7 °C | 951.98 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 | Dfa - Humid Continental Hot Summers With Year Around Precipitation |