A warm Fourth of July, and an even hotter weekend, as heatwave rolls through Southern California

The Fourth of July will be warm and sunny, with an even hotter weekend in store, as temperatures are expected to soar into the triple digits in some areas amid a heatwave making its way across Southern California and other parts of the state.

By Wednesday, a high-pressure system already had settled over the region, with temperatures in the Inland Empire reaching exceeding 100 degrees, according to National Weather Service meteorologist Mark Moede.

A heat advisory was issued in San Bernardino County on Wednesday, with cities including Upland and Ontario reaching into the mid to high 90s. By Friday, those temperatures are expected to climb up to as high as 102 before a slight cooldown heading into Sunday.

Excessive heat watches and warnings have been issued across Southern California and other parts of the country.

“The summer heat can be dangerous, and everyone should take the right steps to stay safe,” San Bernardino County health officer Michael Sequeira said in a news release.

“Heat-related illnesses like heat exhaustion and heat stroke can be very serious,” Sequeira said. “By keeping cool, drinking plenty of water, and staying informed, we can protect ourselves and those we care about.”

The warm, dry conditions also have spurred concerns for additional brush fires.

“Since mid-June we’ve seen a rapid drop-off and drying of moisture despite a very wet winter,” said NWS meteorologist Alex Tardy. “And now conditions of our fuel and vegetation are feeling this heat and are dropping below average and even near record lows.”

“So fire weather conditions are definitely elevated and this is concerning over a holiday weekend,” he said.

Riverside County cities including Hemet had already reached 100 on Wednesday, Moede said, and was expected to climb to around 105 to 107 on Friday and Saturday.

And while evenings will be cooler, it’s all relative. Overnight lows in the Inland Empire will be in the 70s.

There may be new daily records for high temperatures in the coming days, too.

Furnace Creek, home of the visitor center at Death Valley National Park, is expected to reach 129 degrees on Sunday, according to Jenn Varian, a National Weather Service meteorologist.

That 129 degree temperature would tie a record for the date. The all-time high in Death Valley is 134 degrees set July 10, 1913. Temperatures have hit 130 twice, on July 9, 2021 and Aug.16, 2020, according to weather service records.

Heading west to Los Angeles County, sweltering heat would also affect many of the inland cities, with areas like Pasadena reaching up to 106, and Woodland Hills up to 112 on Friday. Coastal cities will feel a bit more relief with highs only reaching into the low to mid 80s on Wednesday and staying consistent through next week.

In Orange County, residents will also get a bit of a break with highs in the high 70s to low 80s on Wednesday without seeing much change heading into the weekend, Moede said. But inland cities like Anaheim and Fullerton will still be breaking a sweat with temperatures reaching the high 80s by Thursday, and into the 90s by Friday.

The heat system’s presence will be felt for the days to come, forecasters said, with warm temperatures expected to persist into much of next week

And while many will be spending some time outside during the Fourth of July holiday and weekend, officials recommend taking extra precautions.

Officials recommend these safety tips for you and your pets:

• Stay in air conditioning, this includes bringing pets indoors

• Limit outdoor activity and avoid direct sunlight. Make sure pets have plenty of access to shade

• Wear loose, lightweight clothing

• Stay hydrated by drinking more water than usual and making sure pets have plenty too

• Check on friends and family members

• Never leave children or pets in a parked vehicle, even if the windows are open