Afternoon highs are expected to soar Wednesday as Southern California braces for the week’s hottest day.

Excessive heat warnings will be in place between 10 a.m. Wednesday and 8 p.m. Thursday for portions of the Antelope Valley where afternoon highs could reach 106 degrees, according to the National Weather Service.

The extreme conditions brought in by building high pressure will increase the potential for heat-related illness, forecasters said.

Hot temperatures
Hot temperatures are expected to continue through Thursday. (National Weather Service)

Similar conditions are expected in Victorville, Hesperia and Apple Valley where an excessive heat warning is in place from 10 a.m. Wednesday to 9 p.m. Friday.

Residents are urged to drink plenty of fluids, stay in an air-conditioned room, stay out of the sun as much as possible and check up on neighbors.

Air quality around the Southland will also take a hit on Wednesday with several cities expecting unhealthy conditions.

Those with respiratory conditions need to be extra cautious, especially in Inland areas like Rancho Cucamonga, Ontario and Redlands.

Good to moderate conditions can be found in communities closer to the coast.

Another hot day is expected for Thursday but the high pressure will begin to break down. Cooler weather is expected to arrive for the weekend.