Rosenberg, Texas has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 15.4 °C (low) to 26.6 °C (high). Annual precipitation averages 1320 Millimeters. Rosenberg is located in USDA Plant Hardiness Zone 9b.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 6.2 °C | 17.3 °C | 100.08 mm |
| February | 8.3 °C | 19.3 °C | 74.68 mm |
| March | 11.7 °C | 22.9 °C | 89.66 mm |
| April | 15.1 °C | 26.3 °C | 104.39 mm |
| May | 19.4 °C | 29.9 °C | 125.98 mm |
| June | 22.6 °C | 32.9 °C | 132.08 mm |
| July | 23.3 °C | 33.9 °C | 98.55 mm |
| August | 23.3 °C | 34.7 °C | 132.08 mm |
| September | 20.9 °C | 32.2 °C | 124.71 mm |
| October | 15.8 °C | 28.2 °C | 116.08 mm |
| November | 10.7 °C | 22.6 °C | 115.82 mm |
| December | 7.1 °C | 18.4 °C | 105.92 mm |
| Annual | 15.4 °C | 26.6 °C | 1320.03 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 |