July 24, 2018

UCS Finds 105-Degree Days in Dallas Metro Area Could Quadruple by Mid-Century, Increase Seven-fold by End of Century

WASHINGTON (July 24, 2018)—In recent weeks, crippling and sometimes deadly heat waves have blanketed many countries around the globe, including Japan, Sweden, the United Kingdom, and now the South-Central United States. While this region of the United States is no stranger to triple-digit temperatures, the events over the last few days have broken records. The Dallas-Fort Worth-Arlington metro area—where temperatures topped out at 109 degrees Fahrenheit—has been hit especially hard. 

Extreme heat in the Dallas-Fort Worth-Arlington metro area is expected to become increasingly commonplace as the planet warms due to human-caused carbon emissions, according to new calculations by the Union of Concerned Scientists (UCS). Between 1979 and 2012, the area observed an average of 13 days annually when the heat index—or “feels like” temperature—exceeded 105 degrees Fahrenheit, the kind of temperatures experienced with the current heatwave. In Dallas, such conditions are likely to prompt the National Weather Service to issue a heat advisory. The number of days when the heat index exceeds 105 degrees Fahrenheit is projected to increase to an average of 56 annually by mid-century, or the equivalent of nearly two months-worth of excessively hot days, according to the UCS findings. By the end of the century the number of dangerously hot days is likely to jump to 94, or the equivalent of more than three months-worth of such conditions, if the Earth’s surface temperature continues to warm at its current rate (reaching 3.7 degrees Celsius by 2100).

“What was once considered record-breaking will soon become the new normal,” said Juan Declet-Barreto, a climate scientist in the Climate and Energy Program at UCS. “The extreme heat in Dallas and elsewhere is one example of what the United States will experience more often if the federal government fails to manage this threat by enacting policies that slow the rate of warming.

“More days of excessive heat can have catastrophic, costly effects on people and communities. High temperatures can increase evaporation, causing plants to lose water and diminishing our water resources. With the energy supply in greater demand during heat waves, blackouts can occur at a time when the loss of air conditioning can be deadly. Likewise, health risks can increase, especially for more vulnerable populations such as children, the elderly, low-income residents and outdoor workers, who may have reduced access to air conditioning and whose bodies may be more sensitive to extreme temperatures.”

UCS only examined how extreme temperatures might increase in the Dallas-Fort Worth-Arlington metro area, but other metro areas in Texas and across the country may see similar increases in the coming decades. Future frequency of deadly heat days could be substantially lower than the UCS analysis projects, however, if global warming emissions are deeply cut—an outcome the global Paris climate agreement is aiming to achieve.

Click here to view a new UCS fact sheet on the connection between climate change and extreme weather events.

If you have any questions or would like to arrange an interview with Juan Declet-Barreto, please contact Ashley Siefert Nunes by email at [email protected] or by phone at 202-331-5666.

The Union of Concerned Scientists puts rigorous, independent science to work to solve our planet's most pressing problems. Joining with people across the country, we combine technical analysis and effective advocacy to create innovative, practical solutions for a healthy, safe, and sustainable future.