Temperatures are expected to jump significantly across Southern California between Tuesday and Thursday this week, which marks the first full week of summer.
The National Weather Service has issued an extreme heat watch for those days, forecasting 90-degree temperatures in downtown Los Angeles and the L.A. metro area — a marked increase from the 75-degree high on Saturday, the last day of spring.
Highs are expected to reach the mid-90s in the San Gabriel Valley and the San Fernando Valley, and possibly climb to 100 degrees or higher in the Antelope Valley and the Cuyama Valley in Santa Barbara County, said Weather Service spokesperson Carol Ciliberti.
Wednesday will probably be the hottest day, she said.
The heat wave stems from “a really strong ridge of high pressure,” Ciliberti said. “It’s centered over Arizona and New Mexico and their southern border with Mexico, but it expands to the west over Southern California.”
She said the increased temperatures bring a higher risk of heat-related illnesses, especially for the young, the elderly and those without air conditioning.
“Do not take your dogs hiking — please,” she said.
The upcoming heat wave should bring a respite from “June Gloom”— the ocean clouds and fog that are typical this time of year — although the familiar marine-layer grayness may soon return. In March, prolonged high temperatures shattered dozens of records in Southern California.
Next week’s expected heat wave brings an elevated risk of fire, the Weather Service noted in an X post, “with drying fuels & tall fire plume potential over the valleys and mountains.”
On Saturday, officials extended a health advisory because of particle pollution from a massive warehouse fire in Boyle Heights. The advisory is in effect until 12:30 p.m. Sunday.
Air quality is expected to range from “unhealthy for sensitive groups” to “very unhealthy” in central Los Angeles County, the San Gabriel Valley, the east San Fernando Valley and the northwest San Bernardino Valley, according to the South Coast AQMD.
The air quality may get worse overnight if winds die down, and if the wind changes direction Sunday morning, smoke may be pushed toward southeast L.A. County, the AQMD said.
Smoke, combined with high humidity, may cause visibility issues overnight, according to the AQMD, and ash could also fall in the area.
If residents smell smoke, they should avoid vigorous physical activity and stay indoors with doors and windows closed, L.A. County public health officials said.
The city of Los Angeles, which has declared a state of emergency, opened a smoke respite shelter at Pecan Recreation Center at 145 S. Pecan St. The county opened one in City Terrace Park at 1126 N. Hazard Ave.
