Houston weather and climate guide

7-day forecast for Houston

Monday in Houston, TX brings sunny then slight chance showers and thunderstorms, with a high near 93°F and a low around 77°F. Across the 7-day outlook, highs average 89°F and lows average 77°F, ranging from 74°F to 93°F. 5 of the 7 days carry at least a 30% chance of precipitation, so keep rain gear handy.

Current conditions

Observed at Houston, Houston Hobby Airport (KHOU) at 3:05 AM CDT.

The humidity is the story

Houston's average August high of 95 °F is not remarkable — Phoenix and Dallas both run hotter. What sets Houston apart is the dew point, which sits near 77 °F through July and August and regularly reaches 80. That combination pushes the heat index past 105 on most summer afternoons and past 110 during a heat wave.

The reason is geography. Prevailing summer winds come from the south and southeast, straight off Gulf water that reaches the high 80s by August. Air crossing water that warm arrives saturated, and there is no terrain between the coast and the city to wring it out. Unlike the Southwest, where hot air is dry and evenings cool off sharply, Houston nights barely improve: overnight lows near 78 with the same humidity mean the body never gets a break.

This is why the heat index matters more here than the temperature. At 95 °F with 30% humidity, sweat evaporates freely and the body copes. At 95 °F with 70% humidity, evaporation nearly stops, and that is Houston from June through September. Outdoor work in this climate requires genuine scheduling around the heat, not just water breaks.

Why Houston floods

Houston has flooded catastrophically several times in two decades, and it is not bad luck. Four factors compound each other.

First, the terrain is almost perfectly flat, with elevation gains of a few feet per mile. Water does not drain; it spreads. Second, the soil is heavy clay with poor infiltration, so rain runs off rather than soaking in even where the ground is undeveloped. Third, the metro area has added enormous areas of impervious surface — parking lots, roads, rooftops — much of it on former prairie that used to absorb rainfall. Fourth, the Gulf supplies moisture for rainfall rates that few places on Earth can match.

Hurricane Harvey in August 2017 made the point permanently. Harvey stalled over southeast Texas for four days and dropped more than 60 inches of rain in parts of Harris County — the highest storm total ever recorded in the continental United States. Roughly a third of Harris County flooded. The wind was a Category 4 at landfall down the coast, but in Houston itself, wind was nearly irrelevant. It was a rainfall event.

The practical lesson for anyone living here is that flood risk is a property-by-property question and standard homeowners insurance does not cover it. A large share of homes flooded by Harvey were outside the mapped 100-year floodplain, and roughly 80% of affected households had no flood insurance.

Hurricane season on the upper Texas coast

The season runs June through November, with the greatest risk from August through early October. The upper Texas coast has a particular vulnerability: the continental shelf here is broad and gently sloping, which allows storm surge to pile up far more than a steeper shelf would. Galveston Bay funnels that water toward the densely populated western shore.

The 1900 Galveston hurricane remains the deadliest natural disaster in United States history, killing an estimated 6,000 to 12,000 people. Hurricane Ike in 2008 drove surge over the Bolivar Peninsula and left millions without power for weeks.

Houston sits far enough inland that surge is not the main threat to the city proper, but it is the main threat to Galveston, Clear Lake, and the communities around the bay — and the Ship Channel's petrochemical infrastructure sits right in the path. Inland Houston's threats are rainfall flooding and, secondarily, wind and prolonged power loss in heat.

Winter: mild, with rare and disruptive exceptions

Winter is genuinely pleasant most years. January averages 63 °F by day, freezes happen a handful of nights, and hard freezes are uncommon. This is the season to be outside here.

The exceptions are severe because nothing is built for them. In February 2021, a stratospheric polar vortex disruption sent Arctic air deep into Texas. Houston fell into the teens and stayed below freezing for days. The state's largely independent power grid, with generation equipment not winterized for sustained cold, came close to complete collapse; millions lost power, water systems failed, and pipes burst across the region. Hundreds of deaths were ultimately attributed to the event.

Ice, not snow, is the routine winter hazard. A freezing rain event glazes elevated highway ramps while surface streets stay wet, which is why the city closes bridges and overpasses that look fine from a distance.

Spring severe weather and the fall reward

Spring brings the year's severe thunderstorm season, generally March through May, when Gulf moisture meets the jet stream. Large hail and damaging wind are the common threats. Tornadoes occur but are less frequent than in North Texas, and Houston-area tornadoes are often embedded in rain-heavy storms that make them hard to see coming — one reason warnings here deserve the same respect they get in Oklahoma.

Late October through early December is the best weather of the year: highs in the 70s, humidity finally down, and the tropical threat fading. If you have a choice about when to visit Houston, this is the window.

Weather hazards to know about

• Flash and river flooding

  Year-round, worst from May through October

  The defining hazard. Rainfall rates of three to five inches per hour happen here, and flat clay terrain cannot drain it. Flood insurance is separate from homeowners coverage and worth having well outside the mapped floodplain.

• Hurricanes and storm surge

  June through November, peaking August to early October

  Rainfall is the main inland threat; surge is the main coastal one, amplified by a broad shallow shelf and Galveston Bay.

• Extreme humid heat

  June through September

  Heat index above 105 on most afternoons, with overnight lows near 78 preventing recovery. Among the most physiologically demanding summer climates in the country.

• Severe thunderstorms

  March through May

  Large hail, damaging straight-line wind and rain-wrapped tornadoes that are difficult to spot visually.

• Hard freezes and ice

  December through February, rare but severe

  Infrastructure is not built for sustained cold, as February 2021 demonstrated. Elevated roadways ice before surface streets.

What to wear and pack, by season

Spring (March to May)

Light layers and rain gear. Warm and humid by April, with thunderstorms arriving fast.

Summer (June to September)

The lightest, most breathable clothing you own, and plan for indoor air conditioning that runs cold. Expect to be damp outdoors regardless of what you wear.

Fall (October to November)

The best season. A light jacket for evenings is all you need through November.

Winter (December to February)

A medium jacket covers most days, but pack for the possibility of a genuine freeze — it happens perhaps once a winter and the city handles it poorly.