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Environment & Climate

Over 80 million under heat alerts as heat dome affects South-Central U.S. and Southwest

A mid-to-late August heat dome is pushing temperatures past 100 degrees and creating elevated heat indices across multiple southern states.

The short version

  • More than 80 million people in the South-Central U.S. and Southwest face Extreme Heat Warnings or Heat Advisories through the week.
  • Heat index values are predicted to range between 105 and 115 degrees in regions including southern Arizona, Texas, Louisiana, and northern Florida.
  • National Weather Service forecasters report that overnight temperatures will offer little cooling relief, increasing the risk of heat-related illnesses.
  • High temperatures in the Southwest are projected to escalate toward 110 degrees or more by mid-week.

Key facts

  • According to the National Weather Service, over 80 million residents are currently subject to Extreme Heat Warnings or Heat Advisories.[NPR]
  • The heat index is projected to reach between 105 and 115 degrees across parts of Texas, Louisiana, northern Florida, and southern Arizona.[NPR]
  • Lawrence Berkeley National Laboratory senior scientist Michael Wehner stated that climate change has driven up standard U.S. heat wave temperatures by 3 to 5 degrees Fahrenheit.[NPR]
  • The frequency of heat waves in the United States has doubled on average since the 1980s.[NPR]

What remains uncertain

  • The exact number of daily high temperature records that will be broken in Arizona and New Mexico remains to be determined as the system expands through the week.[NPR]

Sources