Brownsville, Texas has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 18.5 °C (low) to 28.7 °C (high). Annual precipitation averages 714.8 Millimeters. Brownsville is located in USDA Plant Hardiness Zone 10a.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 10.6 °C | 21.3 °C | 28.7 mm |
| February | 12.7 °C | 23.6 °C | 33.27 mm |
| March | 15.6 °C | 26.1 °C | 34.04 mm |
| April | 18.9 °C | 28.8 °C | 38.35 mm |
| May | 22.3 °C | 31.4 °C | 57.66 mm |
| June | 24.3 °C | 33.7 °C | 67.56 mm |
| July | 24.7 °C | 34.2 °C | 56.39 mm |
| August | 24.8 °C | 34.9 °C | 52.58 mm |
| September | 23.1 °C | 32.6 °C | 142.75 mm |
| October | 19.3 °C | 29.9 °C | 107.44 mm |
| November | 14.8 °C | 25.7 °C | 49.53 mm |
| December | 11.3 °C | 22.1 °C | 46.48 mm |
| Annual | 18.5 °C | 28.7 °C | 714.75 mm |
| Average First Frost Date | Frost Rare |
| Average Last Frost Date | |
| Average Days With Frost | Frost Free |
| Plant Hardiness Zone | Zone 10a : -1.1°C to 1.7°C |
| Plant Hardiness Zone - 2012 | Zone 10a : -1.1°C to 1.7°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |