If you were hoping last week’s heat was the worst of it, I have some unwelcome news. Central Texas is firmly locked in the grip of one of the most persistent heat events of the summer, and there is no meaningful relief on the horizon. A nearly stationary heat dome continues to park itself over the region, and every day this week is shaping up to be another triple-digit affair — with the weekend threatening to be the most dangerous stretch yet.
The Setup: A Heat Dome That Refuses to Budge
The culprit, as it has been all summer, is a powerful upper-level ridge of high pressure sitting over the Desert Southwest and extending deep into Texas. This kind of pattern is the atmospheric equivalent of a lid on a pot — it suppresses cloud formation, forces hot air to sink and compress, and shuts the door on any meaningful storm activity. For most of Central Texas, it’s been roughly a month since a significant rainfall event, and the parched, cracked ground is now amplifying the heat cycle: dry soil absorbs solar energy more efficiently, radiating it back upward and pushing afternoon temperatures even higher than the atmosphere alone would produce.[4]
The result is a forecast that reads like a broken record. Daily high temperatures along the I-35 corridor — think Austin, Round Rock, San Marcos, and Kyle — are expected to reach 100 to 103 degrees through the workweek, with the Hill Country seeing readings in the 98 to 100 degree range.[4] And those are just the actual air temperatures. Heat index values — what it genuinely feels like when you step outside — are a different, grimmer story.
The Heat Advisory: Thursday Through Sunday
The National Weather Service has issued a Heat Advisory running from 2 p.m. Thursday, August 20, through 7 p.m. Sunday, August 23, covering a wide swath of Central Texas counties including Travis, Williamson, Hays, Bastrop, Caldwell, Burnet, Llano, Comal, Bexar, Fayette, and Lee.[3] That covers virtually every major population center from the Austin metro down toward San Antonio.
The NWS is warning that temperatures could reach 104 degrees, with heat index values climbing as high as 112 degrees.[7] To put that in perspective: 112 degrees is the kind of heat index that can overwhelm even a healthy adult in direct sun within a matter of hours. The most dangerous window each day will be roughly 1 to 7 p.m., when afternoon heating peaks and humidity surges back in from the Gulf.[3]
Friday through Sunday looks to be the peak of this particular surge. Morning lows will start in the low 80s, which in itself is oppressive — your body never fully recovers overnight. By afternoon, temperatures will soar to 103 to 106 degrees, with heat indices of 110 or hotter.[5] A weak cold front is expected to push into the Ark-La-Tex region on Friday, bringing some relief to East Texas — but here’s the catch for Central Texas: rather than cooling us down, the compressional heating effect from sinking air on the south side of that boundary could actually make Friday and the weekend hotter than Thursday.[5] That’s a phenomenon worth understanding: when air sinks and is compressed by increasing atmospheric pressure, its temperature rises. We’re essentially getting squeezed by the atmosphere itself.
A Milestone Nobody Wanted
Thursday marks a sobering statistical moment for Austin: it will be the 23rd day this year with temperatures reaching at least 100 degrees.[5] With the current pattern showing no signs of breaking before the end of the month, that number is going to climb considerably higher. The LCRA’s extended outlook through the week of August 31 shows little change — sunny, hot, and dry conditions are expected to persist, with daily highs potentially easing only slightly to around 98 to 100 degrees as the heat dome trends marginally weaker.[2] That is not a forecast that inspires celebration.
Drought Conditions Expanding
The heat isn’t just uncomfortable — it’s actively damaging the region’s water resources. The latest U.S. Drought Monitor report shows that drought conditions across Central Texas expanded over the past week, and without significant rainfall in the forecast, conditions are expected to deteriorate further.[1] This is the compounding crisis that doesn’t always make headlines but matters enormously for the Hill Country’s rivers, the Highland Lakes, and the agricultural communities that depend on them. Every additional day of triple-digit heat without rain deepens the deficit.
Back to School in the Heat
For Austin-area families, there’s an added layer of concern this week: Austin ISD students return to classrooms Tuesday, August 18, and the weather pattern offers essentially no relief for that first day of school.[6] Students waiting at bus stops, walking between buildings, or heading to after-school athletics practice will be stepping into some of the hottest afternoon hours of the year. Parents, please make sure kids have water bottles, and coaches — be vigilant about practice schedules and mandatory water breaks.
The Human Toll: A Public Health Emergency
This isn’t just a weather story. It’s a public health story. Austin Public Health has reported 784 emergency room visits for heat-related illness so far this summer — nearly twice as many as at the same point last year.[7] Austin Public Health Senior Epidemiologist Rina Solanki noted that year-to-year comparisons are complex, but the raw numbers are a clear signal that this heat is hurting people. The most vulnerable populations remain the elderly, young children, outdoor workers, and anyone without reliable access to air conditioning.
Know the warning signs of heat stroke: confusion, loss of consciousness, hot and dry skin, and a body temperature above 103°F. If you encounter someone experiencing heat stroke, move them to a cool, air-conditioned space immediately, cool them with wet cloths or a cool bath, and call 911. Do not give fluids to someone who is unconscious or unresponsive.[3]
What You Should Do Right Now
Here are my concrete, actionable takeaways for the week ahead:
- Limit outdoor activity between 10 a.m. and 7 p.m. If you must be outside, take breaks in the shade or air conditioning every 20–30 minutes.
- Hydrate aggressively — at least 8 ounces of water every 20 minutes during outdoor exertion, even if you don’t feel thirsty.
- Check on neighbors, especially elderly residents who may not have or use air conditioning.
- Never leave children or pets in vehicles, even for a few minutes. Car interiors can reach lethal temperatures in under 10 minutes.
- Know your cooling centers. The City of Austin operates cooling centers during heat advisories — check the Austin Public Health website for current locations.
- Hill Country visitors: If you’re planning a tubing trip or outdoor recreation, go early, bring more water than you think you need, and get off the water by noon.
The Bottom Line
We are deep in what may be the most sustained heat event of the 2026 summer, and the calendar is no guarantee of relief — we’ve seen brutal heat in Central Texas well into September before. The heat dome is stubborn, the drought is worsening, and the weekend heat index values approaching 112 degrees are genuinely dangerous. Stay cool, stay hydrated, and look out for your neighbors. I’ll have an updated outlook next week as we watch for any signs that this pattern is finally ready to break.
References
- Triple-digit heat and expanding drought lock in across Central Texas for another week — FOX 7 Austin — https://www.fox7austin.com/weather/triple-digit-heat-and-expanding-drought-lock-across-central-texas-another-week
- August Heat Wave Continues with Little Relief in Sight — LCRA — https://www.lcra.org/august-heat-wave-continues-with-little-relief-in-sight
- Austin weather: Heat Advisory to be in effect through the weekend — FOX 7 Austin — https://www.fox7austin.com/weather/austin-weather-heat-advisory-august-20-2026
- Triple-Digit Heat and Dry Weather Will Persist throughout the Week — LCRA — https://www.lcra.org/triple-digit-heat-and-dry-weather-will-persist-throughout-the-week
- Austin weather: Triple-digit heat could reach 106 degrees — Austin American-Statesman — https://www.statesman.com/weather/article/austin-weather-heat-forecast-106-degrees-22393429.php
- Austin weather forecast shows how long 100-degree heat will last — Austin American-Statesman — https://www.statesman.com/weather/article/austin-100-degree-heat-back-to-school-forecast-22390397.php
- Austin weather: Heat advisory in effect for most of Central Texas; residents urged to stay safe — FOX 7 Austin — https://www.fox7austin.com/news/austin-weather-heat-advisory-effect-most-central-texas
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