Extreme heat: The hotter days ahead

Enduring summertime heat is a customary part and enduring memory of the Texas experience. This year’s summer has done little to dispel that impression. In fact, recent National Oceanic and Atmospheric Administration data indicates that Texas just had the hottest April through July on record.

But for ice cream merchants, air conditioning vendors and the occasional meteorologist, hot Texas summers rarely provoke any degree of enthusiasm. The shared experience of miserable summer heat prompts reasonable questions about what future summers may hold. Unfortunately, new data points to Texas getting hotter.

Earlier this week the First Street Foundation released a new report on hazardous heat trends.  Using middle-of-the-road modeling scenarios to predict future temperatures, First Street’s analysis anticipates a 3 degree Fahrenheit warming shift across the United States over the next 30 years. As average temperatures warm, higher temperatures will become more frequent.

This is bad for Texas.

Between now and 2053, Texas will experience a dramatic increase in the number of days with a heat index — what the temperature feels like — above 100 degrees, according to First Street’s analysis. In fact, Texas counties account for 16 of the top 20 U.S. counties expected to experience the greatest number of days above 100 degrees over the next 30 years.

In addition to the report, First Street released an interactive map, Heat Factor, that illustrates hot weather trends for Texas’ cities and counties in the coming decades. According to the data, Travis County will go from one day per year with a heat index above 108 degrees to 23 days in 2053. By that same time, Harris County will experience at least 24 days – more than three weeks – with a heat index of 110 degrees or higher. Similarly, Bexar County could endure 22 days with heat indexes above 108 degrees.

First Street’s findings corroborate an earlier report released by Texas 2036 and the Office of the Texas State Climatologist at Texas A&M University on extreme weather trends. That report found that extreme heat has become more frequent and severe, and projects a 40% increase in the number of 100 degree days by 2036 relative to the last century.

These data sets pointing to hotter days ahead raise significant policy implications. For starters, and as observed in Texas 2036’s extreme weather report, warmer temperatures will increase the rate of evaporative losses from our rivers, lakes and reservoirs by 4%, diminishing the amount of available water supplies. This will accelerate the strains on our surface water supplies, which are already stressed during drought.

Hotter temperatures will also increase demands on our energy grid. Texas’ unspoken law of thermodynamics is that when outside temperatures go up, indoor thermostats go down. According to First Street’s analysis, greater air conditioning use will increase statewide electric consumption from 35,117 gigawatt hours in 2023, to 38,308 gigawatt hours by year 2053. This increase in electrical demand for air conditioning alone necessitates the addition of reliable energy supplies.

Lastly, excessive heat damages transportation infrastructure. As already seen in this record hot year, excessive temperatures can warp roads, bridges and railways, and even overheat airport runways. Just as hazards will increase with heat-related damages, so, too, will be the need to repair and rehabilitate transportation infrastructure.

Unfortunately, hot — and potentially hotter — Texas summers are bound to come. In the meantime, policymakers can take needed steps to improve our water, energy and transportation sectors’ resilience to these future extremes.

Interested in other ways the heat is impacting the state? Check out Mazur’s take on how the agriculture sector is reeling from drought.