Map Shows Texas Cities Hit Triple Digits Amid ‘Dangerous’ Heat

Temperatures is Texas reached triple digits on Tuesday as the first heat wave of the warm-weather season sets in over the southwestern United States.

According to the National Weather Service (NWS), “dangerous” heat indexes are expected throughout the week in central and south Texas before temperatures begin to drop again by the weekend. Ground temperatures in San Antonio reached up to 100 degrees on Tuesday, while the city of San Angelo set a daily record high at 111.

An excessive-heat warning was issued by the NWS for the counties surrounding San Antonio, Brownsville and Corpus Christi, Texas, until 8 p.m CDT Tuesday, with heat index values possibly reaching up to 117 degrees. Heat advisories were also in place for the areas around Odessa, Fort Worth, San Angelo and Houston until Tuesday evening.

“Dangerous heat indices expand today and continue through mid week with Heat Advisories each day,” the NWS office for San Antonio said in a post to X, formerly Twitter. “Take precautions in the heat.”

According to the service’s website, heat advisories are issued by the NWS when the maximum heat index temperature is expected to be 100 degrees or higher for at least two days. An excessive-heat warning is issued when the maximum heat index is 105 or higher for at least two days.

Residents who face a heat warning or watch are advised to stay hydrated, keep out of the sun and “check up on relatives and neighbors,” the NWS said. The service also recommends the use of air conditioners, electric fans or taking cold baths or showers.

Heat-related warnings were also issued in California, Nevada, Arizona, Utah and New Mexico this week. The high temperatures are being spurred by a heat dome, a term used to describe a weather event in which high pressure is caught in the atmosphere, trapping hot ocean air like a “lid on a boiling pot.” The phenomenon is moving its way upward into the U.S. from Mexico, which has resulted in 48 deaths since March.

In Southern California, excessive-heat warnings were issued for San Diego, Fresno, Bakersfield and parts of Los Angeles County, where temperatures are forecast to reach up to 108 later this week. Areas in the Sacramento Valley are expected to surpass 110 degrees, while Death Valley National Park could see temperatures from 118 to 122.

Las Vegas is forecast to reach temperatures of 107 to 114 degrees, while in Phoenix, the highs could soar up to 113. Excessive-heat warnings have been issued for most of the day Wednesday in southern Nevada and Arizona.