Rio, Virginia has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 7.3 °C (low) to 19.6 °C (high). Annual precipitation averages 1169.9 Millimeters. Rio is located in USDA Plant Hardiness Zone 7b. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Nov. 1 - Nov. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -3.7 °C | 7.6 °C | 81.79 mm |
| February | -2.7 °C | 9.4 °C | 71.12 mm |
| March | 0.9 °C | 14 °C | 98.55 mm |
| April | 6.4 °C | 20.4 °C | 88.14 mm |
| May | 11.7 °C | 24.2 °C | 113.54 mm |
| June | 16.6 °C | 28.5 °C | 112.52 mm |
| July | 18.8 °C | 30.7 °C | 107.44 mm |
| August | 17.9 °C | 29.8 °C | 97.79 mm |
| September | 14.3 °C | 26.2 °C | 121.41 mm |
| October | 7.6 °C | 20.6 °C | 97.79 mm |
| November | 1.9 °C | 14.7 °C | 88.65 mm |
| December | -1.7 °C | 9.4 °C | 91.19 mm |
| Annual | 7.3 °C | 19.6 °C | 1169.93 mm |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 7b : -15°C to -12.2°C |
| Plant Hardiness Zone - 2012 | Zone 7a : -17.8°C to -15°C |
| Current Drought Conditions | Extreme Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |