LOS ANGELES (KABC) — Starting Tuesday, a severe heat wave will move across Southern California, with temperatures above 30 degrees Celsius expected in many areas.

How hot will it be?

An extreme heat warning has been issued for most of the region, except the coast, for the period Tuesday to Friday.

The National Weather Service expects temperatures to rise several degrees each day, and dangerous heat may occur. (Midweek) in most areas except the beaches.

The days are also getting hotter in the valleys, with triple-digit highs in the Antelope Valley. In the Santa Clarita and San Fernando valleys, temperatures will also rise above 38 degrees from Tuesday, and in the San Gabriel Valley by Thursday.

Night temperatures will also rise and will remain above 20 degrees in the valleys during the second half of the week and into next weekend.

Orange County will also feel the heat, with temperatures in Anaheim rising to around 92 degrees on Wednesday.

Increased fire risk

The hot, dry weather will also increase the risk of fires in the mountains, valleys and deserts throughout the week.

Health authorities urged people to drink plenty of fluids, stay in air-conditioned rooms, avoid the sun, check on relatives and neighbors, and not leave small children or pets in unattended vehicles, as temperatures inside can reach lethal levels within minutes.

Extreme heat in the southwest

ABC News reports that in the Southwest, a heat warning is in effect for 28 million Americans in Southern California, Southern Nevada and Western Arizona.

Cities like Las Vegas, Phoenix, Fresno and Bakersfield are under a heat advisory from Wednesday through Friday, where temperatures could reach 35 to 40 degrees. This advisory will be changed to a heat warning or extreme heat alert the next day.

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City News Service, Inc. contributed to this report.