Rosharon, Texas has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 15.9 °C (low) to 26.2 °C (high). Annual precipitation averages 1385.8 Millimeters. Rosharon is located in USDA Plant Hardiness Zone 9b.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 6.8 °C | 17.3 °C | 107.19 mm |
| February | 8.9 °C | 19.2 °C | 74.42 mm |
| March | 12.1 °C | 22.6 °C | 86.61 mm |
| April | 15.5 °C | 25.8 °C | 100.84 mm |
| May | 19.8 °C | 29.3 °C | 125.73 mm |
| June | 22.9 °C | 32.4 °C | 136.4 mm |
| July | 23.7 °C | 33.3 °C | 110.49 mm |
| August | 23.7 °C | 33.9 °C | 141.99 mm |
| September | 21.5 °C | 31.7 °C | 153.92 mm |
| October | 16.3 °C | 27.9 °C | 127.25 mm |
| November | 11.2 °C | 22.6 °C | 114.81 mm |
| December | 7.8 °C | 18.5 °C | 106.17 mm |
| Annual | 15.9 °C | 26.2 °C | 1385.82 mm |
| Average First Frost Date | Frost Rare |
| Average Last Frost Date | |
| Average Days With Frost | Frost Rare |
| Plant Hardiness Zone | Zone 9b : -3.9°C to -1.1°C |
| Plant Hardiness Zone - 2012 | Zone 9a : -6.7°C to -3.9°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |