Cairo, Ohio has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 5.4 °C (low) to 15.7 °C (high). Annual precipitation averages 1003.6 Millimeters. Cairo 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 | -7.3 °C | 0.6 °C | 71.37 mm |
| February | -6.3 °C | 2.4 °C | 59.94 mm |
| March | -1.7 °C | 8.3 °C | 72.39 mm |
| April | 4.1 °C | 15.8 °C | 96.27 mm |
| May | 10.4 °C | 21.9 °C | 106.68 mm |
| June | 15.8 °C | 26.9 °C | 110.24 mm |
| July | 17.5 °C | 28.7 °C | 104.65 mm |
| August | 16.4 °C | 27.8 °C | 88.39 mm |
| September | 12.4 °C | 24.8 °C | 80.26 mm |
| October | 6.4 °C | 17.7 °C | 72.39 mm |
| November | 0.7 °C | 9.9 °C | 76.71 mm |
| December | -4.1 °C | 3.4 °C | 64.26 mm |
| Annual | 5.4 °C | 15.7 °C | 1003.55 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 100-125 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 |