Sinton, Texas has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 62.3 °F (low) to 81.4 °F (high). Annual precipitation averages 33.5 Inches. Sinton is located in USDA Plant Hardiness Zone 9b.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 45.8 °F | 66.3 °F | 1.71 in. |
| February | 49.7 °F | 70.1 °F | 1.7 in. |
| March | 56.1 °F | 75.2 °F | 2.5 in. |
| April | 62.2 °F | 81.1 °F | 1.86 in. |
| May | 69.7 °F | 86.3 °F | 3.05 in. |
| June | 74.6 °F | 91.4 °F | 3.45 in. |
| July | 75.8 °F | 93.0 °F | 3.24 in. |
| August | 75.8 °F | 94.6 °F | 2.59 in. |
| September | 72.0 °F | 90.6 °F | 5.97 in. |
| October | 63.7 °F | 84.4 °F | 3.65 in. |
| November | 54.5 °F | 75.2 °F | 2.02 in. |
| December | 47.6 °F | 68.4 °F | 1.76 in. |
| Annual | 62.3 °F | 81.4 °F | 33.5 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 9a : 20°F to 25°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |