Sealy, Texas has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 14.5 °C (low) to 26.5 °C (high). Annual precipitation averages 1162.1 Millimeters. Sealy is located in USDA Plant Hardiness Zone 9a. The growing season typically runs from the last frost around Feb. 11 - Feb. 20 through the first frost around Dec. 11 - Dec. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 5.1 °C | 16.8 °C | 95.5 mm |
| February | 7.2 °C | 18.9 °C | 66.55 mm |
| March | 10.7 °C | 22.6 °C | 95 mm |
| April | 14.2 °C | 26.2 °C | 95.5 mm |
| May | 18.7 °C | 29.9 °C | 110.74 mm |
| June | 21.9 °C | 32.8 °C | 112.27 mm |
| July | 22.8 °C | 34.4 °C | 68.83 mm |
| August | 22.6 °C | 35.3 °C | 97.79 mm |
| September | 20.2 °C | 32.4 °C | 107.44 mm |
| October | 14.7 °C | 27.9 °C | 121.16 mm |
| November | 9.6 °C | 22.2 °C | 100.08 mm |
| December | 6.1 °C | 18 °C | 91.19 mm |
| Annual | 14.5 °C | 26.5 °C | 1162.05 mm |
| Average First Frost Date | Dec. 11 - Dec. 20 |
| Average Last Frost Date | Feb. 11 - Feb. 20 |
| Average Days With Frost | 10-20 Days |
| Plant Hardiness Zone | Zone 9a : -6.7°C to -3.9°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 |