Cairo, West Virginia has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 5.3 °C (low) to 18.3 °C (high). Annual precipitation averages 1184.4 Millimeters. Cairo is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -5.9 °C | 4.6 °C | 85.09 mm |
| February | -5 °C | 6.7 °C | 80.52 mm |
| March | -1.4 °C | 12.1 °C | 107.44 mm |
| April | 4.1 °C | 19.6 °C | 98.55 mm |
| May | 9.8 °C | 24.1 °C | 124.21 mm |
| June | 14.7 °C | 28 °C | 116.33 mm |
| July | 17.2 °C | 29.8 °C | 129.03 mm |
| August | 16.3 °C | 29.3 °C | 100.33 mm |
| September | 12.2 °C | 26.2 °C | 91.44 mm |
| October | 5.3 °C | 19.8 °C | 81.03 mm |
| November | -0.3 °C | 12.8 °C | 81.79 mm |
| December | -3.4 °C | 6.9 °C | 88.65 mm |
| Annual | 5.3 °C | 18.3 °C | 1184.41 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| 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 |