Labor Day is over, but summer is not over yet: A late heat wave hit the region on Wednesday, with triple-digit temperatures expected for the rest of the week.

Meteorologists with the National Weather Service said the “dangerous heat wave” will last at least through Friday, and although temperatures will drop somewhat over the weekend, many areas will still be warmer than average.

“The theme this week is heat. And for some coastal and valley areas, this could be the hottest summer yet,” the NWS said. “The combination of a very strong high pressure system aloft and pressure gradients rotating slightly offshore are the ingredients that will drive temperatures to near 100 degrees in some inland coastal areas and 110 to 115 degrees in the warmer valleys.”

Maximum temperatures are expected to rise gradually each day this week, with even the traditionally cooler coastal areas seeing temperatures 3 to 6 degrees above normal.

A heat advisory went into effect Tuesday morning in the western San Fernando Valley and will remain in effect until 8 p.m. Friday. According to the NWS, Thursday and Friday will be the hottest days in the region, with temperatures reaching 115 degrees.

“There is a probability of about 30% that temperatures will reach 46 degrees or even higher locally on Thursday,” meteorologists said.

Another extreme heat warning goes into effect at 11 a.m. Wednesday and remains in effect until 8 p.m. Friday for the Santa Monica Mountains Recreation Area, Calabasas, eastern San Fernando Valley, San Gabriel Mountains, Antelope Valley and foothills, San Gabriel Valley, inland coast including downtown Los Angeles, and the 5 and 14 Freeway corridors.

Maximum temperatures of between 35 and 43 degrees Celsius are expected in these areas, with Thursday and Friday again being the hottest days.

From 11 a.m. Thursday to 8 p.m. Friday, a less severe heat warning is in effect for Los Angeles beaches, the Palos Verdes Hills and the Malibu coast; highs of up to 90 degrees are possible.

Due to the intense heat, the South Coast Air Quality Management District has issued an ozone warning that will remain in effect until 8 p.m. Friday as elevated smog levels are expected due to the heat wave. According to the AQMD, ozone levels in the Santa Clarita Valley and parts of the San Gabriel Valley are expected to reach health-threatening levels or higher by Friday.

Downtown Los Angeles reached 90 degrees Fahrenheit on Labor Day on Monday, but temperatures are expected to rise to 98 degrees on Thursday and 90 degrees on Friday, according to the NWS.

It was 99 degrees in Van Nuys on Monday and temperatures were expected to be just above 100 degrees for the rest of the week, as were Burbank and Pasadena.

In West Hollywood, the temperature was 88 degrees on Monday, with highs of 96 degrees expected on Thursday and Friday.

Woodland Hills is expected to see highs of 43 degrees for three consecutive days starting Wednesday, while Lancaster is forecast to see temperatures as high as 41 degrees on Thursday and Friday.

Night temperatures are also rising and are expected to remain above 21 degrees in the valleys until the weekend.

Orange County also felt the heat: Anaheim reached 32 degrees on Monday and is expected to reach 32 degrees on Wednesday, 34 degrees on Thursday and 36 degrees on Friday. In Irvine, 34 degrees were expected on Thursday and 35 degrees on Friday.

From 11 a.m. Wednesday to 8 p.m. Friday, a heat warning is in effect for inland Orange County and the Santa Ana Mountains and Foothills; temperatures may reach up to 40 degrees Celsius.

Heat warnings are in effect from 11 a.m. Thursday to 8 p.m. Friday for coastal areas of Orange County, where temperatures could reach 35 degrees.

Authorities advised the population to drink plenty of fluids, stay in air-conditioned rooms, avoid the sun and check on relatives and neighbors.

Residents were also urged never to leave children or pets in unattended vehicles as temperatures can become fatal in minutes.

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

“A slow cooling trend will begin on Saturday, but heat threats may need to continue for at least another day,” forecasters said. “By Sunday, it is expected to have cooled enough to lift heat warnings, but some warnings may need to remain in effect inland as highs will still be in the 100-107 degree range.”