South Lebanon, 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 18.1 °C (high). Annual precipitation averages 1115.3 Millimeters. South Lebanon 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. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -5.3 °C | 4 °C | 82.55 mm |
| February | -4.2 °C | 6.2 °C | 69.34 mm |
| March | 0.1 °C | 11.7 °C | 98.04 mm |
| April | 5.6 °C | 18.4 °C | 116.59 mm |
| May | 11.4 °C | 23.8 °C | 124.97 mm |
| June | 16.4 °C | 28.2 °C | 113.54 mm |
| July | 18.4 °C | 30.2 °C | 104.65 mm |
| August | 17.4 °C | 29.7 °C | 90.17 mm |
| September | 12.9 °C | 26.6 °C | 72.14 mm |
| October | 6.4 °C | 19.8 °C | 78.23 mm |
| November | 0.7 °C | 12.3 °C | 78.49 mm |
| December | -2.6 °C | 6.3 °C | 86.61 mm |
| Annual | 6.4 °C | 18.1 °C | 1115.32 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| 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 |