Rio Grande, Ohio has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 6.1 °C (low) to 18.6 °C (high). Annual precipitation averages 1112.8 Millimeters. Rio Grande 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. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -5.2 °C | 4.9 °C | 81.79 mm |
| February | -4.2 °C | 7.1 °C | 77.22 mm |
| March | -0.4 °C | 12.4 °C | 101.09 mm |
| April | 5.1 °C | 19.7 °C | 94.23 mm |
| May | 10.8 °C | 24.2 °C | 114.3 mm |
| June | 15.6 °C | 28.3 °C | 108.46 mm |
| July | 17.8 °C | 30.2 °C | 119.63 mm |
| August | 16.8 °C | 29.6 °C | 88.9 mm |
| September | 12.8 °C | 26.5 °C | 89.15 mm |
| October | 6.2 °C | 20.1 °C | 77.98 mm |
| November | 0.6 °C | 13.1 °C | 72.39 mm |
| December | -2.7 °C | 7.2 °C | 87.63 mm |
| Annual | 6.1 °C | 18.6 °C | 1112.77 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| 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 6b : -20.6°C to -17.8°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |