Climate change intensifying record-breaking May heat in Texas

Correction: A previous version of this Climate Shift Index Alert quoted the National Weather Service as saying “one of the most dramatic early-season temperature swings in state history…” The correct quote is “one of the more dramatic temperature swings in recent memory...”

One of the hottest May heatwaves on record is set to begin Tuesday, May 13, across Texas, bringing what the National Weather Service has called “one of the more dramatic temperature swings in recent memory…”

Extreme heat will build rapidly, with daily and monthly high-temperature records likely to be tied or broken from May 13 through the weekend. Climate Central analysis shows this level of early-season heat would have been extremely rare without human-caused climate change. 

Note: This event is expected to continue beyond May 16. Use the Global Climate Shift Index map to stay updated on heat in your region.

How unusual is the forecasted heat?

• High temperatures are forecast to run 10°F to 25°F above average across much of Texas, including Austin, San Antonio, Houston, College Station, Dallas–Fort Worth, and Laredo. 

• Central and South Texas will see highs of 100°F-105°F starting Tuesday. The most intense heat is forecast for Wednesday, when temperatures may exceed 110°F in Southwest Texas.

• Daily high-temperature records are likely to break in multiple cities, with some all-time May heat records in jeopardy between Tuesday and Friday.

• The weather pattern is driven by a high-pressure system over Mexico, combined with a large low-pressure system over the northern U.S., funneling hot, dry air into Texas.

How has climate change influenced this heat?

• From May 13-16, several Texas cities, including Austin, San Antonio, Waco, and Laredo, are expected to hit a Climate Shift Index (CSI) level of 5 for one day or more. A CSI level 5 indicates an exceptional climate-driven event. 

• Over the entire period, 9.2 million people in Texas will experience a CSI level 5.

• 23.8 million people — 76% of the population — will experience at least one day with a CSI level of 3, indicating that human-caused climate change made this heat at least 3 times more likely,  including in Houston, Corpus Christi, and College Station.

What impact could this extreme heat have?

• The National Weather Service categorizes this event as carrying a “major to extreme” heat risk due to the early-season timing — before most people have acclimated to summer heat.

• This level of extreme heat typically occurs in short periods in July or August, making its arrival in May particularly unusual and dangerous.

• Health risks include heat exhaustion and potentially fatal heat stroke, especially for outdoor workers like those in agriculture or construction.  

What do experts say?

Dr. Kristina Dahl, VP of Science at Climate Central, said: 
“This kind of extreme heat in May is not just unusual — it’s a clear signal of our changing climate,” said Dr. Kristina Dahl, VP of Science at Climate Central. “Temperatures this high, this early in the year, would have been extremely rare in the past. But due to human-caused climate change, these dangerous heat waves are becoming more frequent, more intense, and more disruptive.”

To request an interview with a Climate Central scientist, please contact Abbie Veitch at aveitch@climatecentral.org. 

How do we know climate change is influencing this heat?

The Climate Shift Index uses peer-reviewed methodology and real-time data to estimate how climate change has increased the likelihood of a particular daily temperature.

Reporting resources

• Climate Shift Index in KML format

• Climate Central’s Interactive Local Records Tracker