Heat index could reach 109°F as residents face another day of above-average temperatures; officials urge heat precautions and storm awareness
HOUSTON, Sept. 15, 2026 — Houston is facing another day of dangerous heat, with a Heat Advisory remaining in effect until 7 p.m. Tuesday as temperatures climb into the mid-90s and the heat index could reach 109°F, according to the National Weather Service.
The heat comes with a chance of scattered afternoon showers and isolated thunderstorms. While widespread rainfall is not expected, forecasters say some storms could produce heavy rain and lightning, creating an additional risk for people outdoors.
Tuesday’s high is expected to reach about 95°F, well above Houston’s average September high of around 90 degrees. There is a 20 percent chance of showers and thunderstorms during the afternoon, with light southeast winds increasing to between 5 and 10 mph.
Heat remains the main public-safety concern
From a disaster-management perspective, the combination of high temperatures and humidity remains the immediate concern for residents.
The National Weather Service is urging people to stay hydrated, take frequent breaks from the heat and use air-conditioned spaces when possible. Outdoor workers, older adults, children and people with existing health vulnerabilities may face greater risks during prolonged exposure to extreme heat.
Residents are also advised to avoid strenuous outdoor activity during the hottest part of the day and to check on relatives, neighbours and others who may need assistance.
The Heat Advisory is scheduled to expire at 7 p.m. Tuesday, but hot conditions are expected to continue through the week, with temperatures remaining in the 90s.
Limited rain expected through midweek
Wednesday is expected to remain mostly sunny, with a high near 93°F and a 20 percent chance of afternoon showers or thunderstorms.
Rain chances could increase on Thursday, when forecasters are calling for a 40 percent chance of showers and thunderstorms. By Friday and Saturday, conditions are expected to become drier and sunnier, with temperatures closer to seasonal averages.
For emergency preparedness, residents should continue monitoring local weather alerts rather than assuming that a lower rain probability means there is no storm risk. Short-lived thunderstorms can still bring lightning, heavy rainfall and sudden changes in conditions.
Tropical activity being monitored
Forecasters are also watching a disturbance in the Atlantic near Bermuda. The system has a 40 percent chance of developing over the next seven days, while its chance of development during the next two days remains very low. It is currently not considered a threat to Texas.
The Pacific remains more active, with Tropical Depression Fifteen-E being monitored for possible further development, along with another area of low development potential.
For Houston residents, however, the immediate priority remains local weather hazards — particularly heat exposure and isolated thunderstorms — rather than tropical storm impacts.
Preparedness remains key
With extreme heat continuing into another day, emergency-management officials and weather authorities are reminding residents that preparation does not have to wait for a major storm or hurricane.
Keeping drinking water available, limiting exposure during peak afternoon heat, knowing where to find air-conditioned shelter and staying informed through official weather alerts can reduce the risk of heat-related emergencies.
As Houston moves through another stretch of summer-like weather, residents are being urged to treat the Heat Advisory seriously while remaining alert for sudden thunderstorms throughout the afternoon.
