Severe Weather Overview

Severe weather in Greater Houston is not a single phenomenon. The region sees frequent thunderstorms throughout the warm season, occasional tornadoes embedded in those storms or in landfalling tropical systems, sustained extreme heat from May through September, and rare but consequential winter events. Each of these hazards interacts with the region's roadway network, power grid, and outdoor workforce in ways that ripple through daily life.

Thunderstorms and Tornadoes

Houston thunderstorms can produce intense rainfall, frequent lightning, damaging straight-line winds, and small hail. The region averages a handful of tornadoes each year, most often in spring or in association with hurricanes making landfall nearby. Tornado warnings should be taken seriously even when skies look unremarkable — the warning signal from the National Weather Service is the trigger to move to an interior room on the lowest floor.

Extreme Heat

Summer heat is the most consistently dangerous weather hazard in Houston, and one of the most underestimated. Heat-related illness disproportionately affects outdoor workers, older adults, young children, and households without reliable air conditioning. The combination of high temperatures and high humidity produces heat index values that can exceed 110 degrees for days at a time. See our extreme heat page for more detail.

Winter Weather

The February 2021 winter storm exposed vulnerabilities in the regional power grid, water system, and building stock that few Houstonians had imagined. Cold-weather events are comparatively rare on the upper Texas coast, which is exactly why they are dangerous: pipes, vehicles, and homes are not built or maintained for sustained freezes. Our winter storms page covers preparation.

Roadway Impacts

Each of these hazards changes how Houston-area roadways behave. Heavy rain produces flash flooding and hydroplaning; thunderstorms reduce visibility; high winds challenge high-profile vehicles; ice and freezing rain make bridges and overpasses treacherous. The Houston metropolitan area carries some of the heaviest commercial truck traffic in the country along I-10, I-45, I-69, I-610, Beltway 8, and the Grand Parkway, which adds further considerations during severe weather. See our road conditions page for detailed driving guidance.