“Hydrate frequently!”

That’s the message the National Weather Service is sending to Las Vegas Valley residents as an extreme heat warning takes effect at 11 a.m. today, thanks to a heat dome that is sitting over the Southwest.

The warning doesn’t expire until 8 p.m. Sunday. The forecast high for today is 94 degrees, which would break the 2017 record of 90 degrees. The hottest temperature ever recorded in March in Las Vegas is 93, set in 2022.

Harry Reid International Airport recorded 88 degrees Tuesday, said Julie Phillipson of the National Weather Service. It was the warmest day of the year in the valley.

There is a 50 percent chance the valley will see 100 degrees on Friday, a 40 percent chance Saturday, the NWS said.

Las Vegas has never seen 100 in March. Or even April. The earliest 100-degree recording took place on May 1, 1947. Even more astounding, the valley rarely sees 90 degrees in March. The average daytime high in mid-March is in the low 70s.

The March heat is a continuation of a theme. Last month was the second-warmest February in the valley since record-keeping began in 1937. January 2026 was the fifth-warmest January on record.

Las Vegas is on track to experience its warmest winter on record, with temperature outlooks forecasting a toasty spring to come, weather scientists say.

March weather facts

— On March 1, Harry Reid International Airport registered 86 degrees, breaking the previous record of 82 degrees set in 1986.

— Las Vegas’ earliest 90-degree day happened on March 13, 2007.

— On March 26, 2025, Las Vegas recorded its first 90-degree day of the year. The temperature later reached 92 degrees.

— The warmest March happened in 2015 (66.7 median degrees).

— Las Vegas saw three 90-degree days in 2004, the most ever for March.

— The average first 90-degree day is April 15.

Contact Mark Davis at mdavis@reviewjournal.com.