Temperatures will climb well into triple-digits over a widespread area of Southern California with the warmest days of the week on the horizon.

Temperatures through Friday in the valleys and inland communities will reach triple digits. Expect highs in the mid- to high-90s in the Los Angeles basin and high-80s on the coast for the rest of the week.

Temperatures have increase by a few degrees each day this week with the high expected to reach the mid-90s in the LA basin by Wednesday. Triple-digit heat will spread into the valleys by Thursday.

Nighttime temperatures will remain in the 70s in the valleys this week.

Inland areas will see highs around 105 to 110 degrees. Some parts of the Inland Empire and San Fernando Valley might reach 112 degrees.

An excessive heat warning for all of Southern California with the exception of coastal communities will begin Wednesday and continue through Friday. Thursday and Friday will be the warmest days of the week, when temperatures will run 10 to 15 degrees above average.

“Dangerous heat is on the way, and it’s going to be like this for the next three days, if not hotter,” said NBCLA forecaster Shanna Mendiola. “We don’t get a break overnight. Those warm lows are going to stick with us for the next few nights.”

Elevated wildfire conditions will accompany the hot and dry weather in the mountains, valleys and deserts.

The South Coast Air Quality Management District issued an ozone advisory that will be in place until 8 p.m. Friday due to anticipated elevated smog levels because of the heat wave. The ozone level is expected to reach the unhealthy level or worse in the Santa Clarita Valley and portions of the San Gabriel Valley through Friday, according to the AQMD.

“It’s going to be very hot,” said Mendiola. “The heat is going to cook up some of the ozone. What is ozone? It’s kind of the pollution that we have in the air. With the heat, it’s not going to get any better. You may see some haze outside, and that’s an indication that the air quality is not the best.”

Click here for cooling centers in Los Angeles County.

An excessive heat warning is in effect across SoCal as high temperatures stick around this week. Annette Arreola reports for the NBC4 News at 6 a.m. on Sept. 4, 2024. 

Tips to stay cool in the heat

Scroll for tips to stay cool this week.

• Stay hydrated! The more hydrated you are, the more effective your body will be at keeping you cool. Drink water – not fizzy and alcoholic drinks, which will dehydrate you.
• Avoid exercise in the middle of the day. If you need to exercise outside, do it early in the morning when the temperature is lower.
• Wear lightweight, light-colored natural fabrics like cotton and linen, as these will help your skin breathe and let your sweat evaporate, cooling you down.
• We sweat around half a pint daily from both feet (and we wonder why they stink!), so if you can, wear sandals or flip-flops to let your foot sweat evaporate.
• Use a fan to circulate air from open windows. Keep your blinds or curtains drawn during the day, so your home doesn’t heat up while you’re out. Turn off big appliances and help prevent brown-outs!
• To cool down quickly, run your wrists under a cold tap or keep a water spray in the fridge for a quick cooling spritz to the face.
• Keep some wet wipes in your bag so you can freshen up your hands, face and neck if you get hot or clammy.
• Want to stay cool at night? One way is to wash your feet in cool water or take a cold shower before bedtime – especially if you get hot during the night or have hot sweats.
• To cool down in bed, try keeping your pillowcase or sheets in a plastic bag in the fridge during the day. Put them back on the bed at night. The fabric will stay cool when you’re trying to get to sleep.
• And bring your pets in and make sure they have shade and water.
• Be prepared for power outages and know where cooling centers are!