High surf, scorching temperatures in the forecast for Orange County cities

The mercury in Orange County is rising yet again — this time to the mid-80s and low 90s along the coast — as the summer’s second heat wave scorches local cities.

The National Weather Service on Monday issued a heat advisory warning of high temperatures brought by a bout of high pressure to the region. The oppressive heat is expected to let up by Friday, according to forecasters.

High temperatures predicted for this week aren’t expected to be as severe as the heat wave that sent the mercury above the 100-degree mark in Costa Mesa and Fountain Valley earlier this month.

Forecasters said temperatures are expected to linger in the mid-80s in Newport Beach, Huntington Beach and Laguna Beach. Costa Mesa and Fountain Valley will be a bit hotter with temperatures reaching the low 90s by Tuesday.

Those looking to escape the oppressive heat with a trip to the beach will be greeted with larger-than-normal surf, due to a southerly swell that began building Monday and is expected to last through Wednesday night, according to the National Weather Service.

South-facing beaches in Newport, Huntington and Laguna are expected to be pounded with waves between 5 feet and 9 feet, with larger sets at some beaches.

In addition to the surf, strong rip currents could pose a danger to swimmers, forecasters said.

Newport Beach lifeguard Battalion Chief Mike Halphide said the department has added additional lifeguards to patrol certain hot areas along the beach, namely the Wedge. Rescue boats will also be on the lookout for distressed swimmers, he said.

As temperatures began to climb on Monday, crowds flocked to the ocean for some relief in the 65-degree water.

“There are a lot of people down here,” Halphide said. “There’s already a good crowd. It looks more like a Friday or Saturday than a Monday.”

hannah.fry@latimes.com

Twitter: @HannahFryTCN