Heat wave reaches 'the tail end' in Southern California

RIVERSIDE, CA - SEPTEMBER 27, 2022: With temperatures reaching triple-digits on Tuesday, a resident takes advantage of the 90 degree temps at dusk to get in a jog with his dog at Challen Park on September 27, 2022 in Riverside, California. The September heat wave brought triple-digit temps to the Inland Empire as the National Weather Service issued heat warnings for Southern California for the week.(Gina Ferazzi / Los Angeles Times)
A man jogs with his dog at Challen Park in Riverside on Tuesday. (Gina Ferazzi / Los Angeles Times)

Southern California hit the tail end of its mini-heat wave, with temperatures in some areas reaching triple digits on Wednesday before the weekend brings an expected cooldown.

Some areas in the region — Riverside and San Bernardino counties — experienced wet conditions after thunderstorms developed Wednesday afternoon.

The National Weather Service in Oxnard ended a heat warning Wednesday evening for the San Gabriel, Santa Clarita and San Fernando valleys and brought the Santa Monica Mountains into the fold. A heat advisory for the Ventura County valleys also ended Wednesday.

According to the Oxnard bureau, parts of the valleys, foothills and mountains were expected to reach as high as 105 degrees. Burbank, which hit 99 degrees on Tuesday, reached 98 degrees Wednesday. Woodland Hills hit the 105-degree mark, up from 102 on Tuesday. Lancaster reached 100 degrees.

The heat advisories and excessive heat warnings for the Los Angeles County coast expired Tuesday evening, said Todd Hall, a meteorologist with the NWS in Oxnard. He added that coastal areas would be a few degrees lower than the previous day.

An excessive heat warning for the Inland Empire, inland Orange County and the lower desert areas ended Wednesday, according to the National Weather Service in San Diego.

The Orange County coast and the San Diego County coast and valleys were under a heat warning until 8 p.m. Wednesday.

The heat wave closing out September is cooler and shorter than the marathon heat wave that kicked off the month, which lasted 10 days and shattered records across the state.

No record-breaking temperatures were reported Wednesday.

"This is a hotter pattern, but this time of year we have had some much hotter weather," said Greg Martin, a meteorologist with the NWS in San Diego.

Temperatures should begin to cool off Thursday and gradually decline into the weekend, meteorologists said.

“We are at the tail end of this,” Hall said.

By Wednesday afternoon, thunderstorms had started to develop west of Twentynine Palms, with wet conditions expected across the mountains, high desert and eastern portions of the inland valleys through the afternoon. The National Weather Service in Phoenix issued flash flood warnings for Riverside and San Bernardino counties that ended Wednesday evening.

Times staff writer Melissa Gomez contributed to this report.

This story originally appeared in Los Angeles Times.