Labor Day may have come and gone, but summer isn’t over yet. A late-night heat wave will sweep across the region on Wednesday, and temperatures are expected to soar into the triple digits for the rest of the week.

According to meteorologists at the National Weather Service, the “dangerous heat wave” will continue at least until Friday. Although temperatures will drop slightly over the weekend, many areas will still be warmer than normal.

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

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

An extreme heat warning went into effect Tuesday morning in the western San Fernando Valley and will remain in effect until 8 p.m. Friday. The NWS says Thursday and Friday will be the hottest days in that area, with temperatures reaching 240 degrees.

“There is about a 30% chance that temperatures will rise to 46 degrees Celsius or even locally higher on Thursday,” meteorologists said.

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

Temperatures of 35 to 43 degrees Celsius are expected in these areas, with Thursday and Friday as the hottest days.

From Thursday 11:00 a.m. to Friday 8:00 p.m., a less strict heat advisory is in effect for the beaches of Los Angeles, Palos Verdes Hills and the Malibu coast, with possible highs of up to 32 degrees Celsius.

Due to the high temperatures, the South Coast Air Quality Management District has issued an ozone advisory that will remain in effect until 8 p.m. Friday due to expected elevated smog levels from the heat wave. According to the AQMD, ozone levels are expected to reach unhealthy levels or worse in the Santa Clarita Valley and parts of the San Gabriel Valley through Friday.

Downtown Los Angeles hit 90 degrees Fahrenheit on Monday, the Labor Day holiday. That’s expected to rise to 100 degrees Fahrenheit on Thursday and 100 degrees Fahrenheit on Friday, according to the NWS.

In Nuys, temperatures reached 99 degrees on Monday and are expected to remain around 100 degrees for the rest of the week, as will Burbank and Pasadena.

West Hollywood had a temperature of 88 degrees on Monday, while highs of 96 degrees are expected on Thursday and Friday.

Woodland Hills is expected to hit 110 degrees Fahrenheit for three straight days starting Wednesday, while Lancaster is expected to hit 106 degrees Fahrenheit on Thursday and Friday.

Temperatures will also rise at night and are expected to remain around 21 degrees in the valleys until the weekend.

Orange County also felt the heat, with Anaheim reaching 89 degrees on Monday and expected to reach 96 degrees on Wednesday, 98 degrees on Thursday and 97 degrees on Friday. Irvine was expected to reach 96 degrees on Thursday and 95 degrees on Friday.

An extreme heat warning is in effect from 11 a.m. Wednesday through 8 p.m. Friday for inland Orange County and the Santa Ana Mountains and Foothills, with temperatures likely to reach 104 degrees Fahrenheit.

Heat warnings are in effect from 11 a.m. Thursday through 8 p.m. Friday for coastal areas of Orange County, where temperatures could reach 95 degrees Fahrenheit.

Authorities warned residents to drink plenty of fluids, stay in air-conditioned rooms, stay out of the sun and keep in touch with family and neighbours.

Residents were also urged to never leave children or pets unattended in vehicles, as temperatures inside these vehicles can become life-threatening within minutes.

The warm, dry weather will also create more fire conditions in the mountains, valleys and deserts throughout the week.

“A slow cooling trend begins Saturday, but heat hazards may continue for at least another day,” meteorologists said. “Enough cooling is expected by Sunday to end heat warnings, but some warnings may need to continue inland with highs still in the 100-107 range.”