San Antonio is starting Thursday under clear skies and muggy air near 80 degrees, but the calm morning is a brief pause before another dangerous round of summer heat. Temperatures are expected to climb to 102 degrees this afternoon, with heat index values reaching as high as 109. Rain is not in the forecast to offer much of a break.
Heat Advisory Covers San Antonio Through Sunday
A Heat Advisory is in effect from 2 p.m. Thursday through 7 p.m. Sunday for the I-35 Corridor and surrounding areas, including San Antonio. The National Weather Service warns that hot temperatures and high humidity could cause heat illnesses, with some locations expected to reach heat-index readings as high as 112.
Thursday's south-southeast wind will stay light near 5 mph, offering little relief from the afternoon sun. Tonight will remain mostly clear, with a low around 79 and evening heat-index values potentially reaching 107; gusts could reach 20 mph.
Triple-Digit Heat Stays Through Next Week
The heat barely backs off Friday, when San Antonio is again forecast to reach 102 degrees with a heat index near 109. Saturday could be the hottest day of the stretch at 103 degrees, followed by highs near 102 Sunday and Monday.
Tuesday and Wednesday are forecast to remain sunny and near 101 degrees, while overnight lows mostly settle between 79 and 80. Rain chances stay at or below 4% through Wednesday, making this a long, dry run of heat rather than a stormy summer pattern.
Outdoor Plans Need A Cooler Strategy
Residents should drink plenty of water, take frequent breaks in shade or air conditioning, and avoid strenuous outdoor work during the hottest part of the afternoon. Lightweight clothing can help, but it will not replace cooling breaks when the heat index pushes well above 100.
Older adults, children, outdoor workers, people without reliable air conditioning and pets face higher risks during the prolonged heat. Check on neighbors and relatives, never leave anyone in a parked vehicle, and move anyone showing signs of heat exhaustion or heat stroke to a cool place; heat stroke is an emergency requiring a call to 911.
