Rio Bravo, Texas has a Hot Semi-Arid Climate climate (Köppen classification: BSh). Average annual temperatures range from 63.3 °F (low) to 86.3 °F (high). Annual precipitation averages 20.3 Inches. Rio Bravo is located in USDA Plant Hardiness Zone 9b.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 46.6 °F | 69.2 °F | 0.87 in. |
| February | 50.7 °F | 74.0 °F | 0.76 in. |
| March | 57.5 °F | 81.0 °F | 1.54 in. |
| April | 63.7 °F | 88.4 °F | 1.43 in. |
| May | 70.9 °F | 94.0 °F | 2.74 in. |
| June | 75.8 °F | 99.1 °F | 1.93 in. |
| July | 76.7 °F | 100.3 °F | 1.78 in. |
| August | 77.0 °F | 100.9 °F | 1.46 in. |
| September | 72.8 °F | 94.2 °F | 3.84 in. |
| October | 65.1 °F | 87.2 °F | 1.78 in. |
| November | 55.1 °F | 77.3 °F | 1.18 in. |
| December | 48.0 °F | 69.9 °F | 0.95 in. |
| Annual | 63.3 °F | 86.3 °F | 20.26 in. |
| Average First Frost Date | Frost Rare |
| Average Last Frost Date | |
| Average Days With Frost | Frost Rare |
| Plant Hardiness Zone | Zone 9b : 25°F to 20°F |
| Plant Hardiness Zone - 2012 | Zone 9b : 25°F to 20°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | BSh - Hot Semi-Arid Climate |