A heat wave is expected to bring a sweltering start to summer for much of Northern California, causing the Bay Area’s air quality to fall to unhealthy levels as temperatures soar into the 90s and 100s.

A Spare the Air alert was issued for Tuesday for the entire Bay Area — meaning unhealthy ground-level ozone levels are expected to cause trouble breathing for people with asthma and other respiratory ailments, according to the Bay Area Air Quality Management District. The warning comes as a ridge of high pressure builds over the region, causing temperatures to rise 10 to 20 degrees above normal for the longest day of the year.

“It’s going to make a hot start of the summer,” said Emily Heller, a National Weather Service meteorologist. “I just advise people to take breaks outside and stay hydrated.”

The National Weather Service issued a heat advisory from 10 a.m. until 10 p.m. Tuesday for almost all of the Bay Area, including the entire East Bay coastline, the Santa Clara Valley, the Santa Cruz Mountains and the inland areas of Napa, Sonoma and Contra Costa counties. Also included were the Sacramento Valley and the northern portion of the San Joaquin Valley.

SAN LEANDRO, CA - CA: Visitors fly kites at Marina Park on Monday, June 20, 2022, in San Leandro, Calif. Temperatures are expected to warm throughout the Bay Area this week. (Aric Crabb/Bay Area News Group)
SAN LEANDRO, CA – CA: Visitors fly kites at Marina Park on Monday, June 20, 2022, in San Leandro, Calif. Temperatures are expected to warm throughout the Bay Area this week. (Aric Crabb/Bay Area News Group) 

Oakland is expected to reach 90 degrees on Tuesday, while San Jose is expected to top out at 98 degrees. Inland portions of the East Bay could see triple-digit highs, including Livermore, which is expected to reach 101 degrees on Tuesday.

The hot start to the season should linger for a couple days, with temperatures dipping only a few degrees on Wednesday before declining further toward the end of the week.  Many places — such as San Jose and inland portions of the East Bay — could see temperatures remain in the 90s through at least Friday.

A heat wave that saw triple-digit temperatures in the region earlier this month was significantly shorter, with a drop of some 20 degrees within two days.

The only places spared from the heat will be cities along the coast, which could benefit from unseasonably cool temperatures in the Pacific Ocean. A weak, offshore low-pressure system could keep temperatures somewhat in check in San Francisco and at the Marin Headlands and Point Reyes.

Little wind is expected to accompany the heat — a blessing in limiting fire conditions across the Bay Area but a curse in that it will cause the air to grow stagnant with pollution, meteorologists and air quality experts said Monday.

FREMONT, CALIFORNIA - June 20: Canada geese drink from a creek at Central Park in Fremont, Calif., on Monday, June 20, 2022. (Dai Sugano/Bay Area News Group)
FREMONT, CALIFORNIA – June 20: Canada geese drink from a creek at Central Park in Fremont, Calif., on Monday, June 20, 2022. (Dai Sugano/Bay Area News Group) 

Air quality on Tuesday is expected to be the worst in the East Bay and the Santa Clara Valley, though residents across the Bay Area are advised to limit outdoor activities during the hottest part of the day, said Aaron Richardson, spokesperson for the Bay Area Air Quality Management District.

He added that residents should try to work remotely Tuesday or take public transit to reduce smog.

“There’s a lot of people with respiratory conditions and susceptibilities to air conditions,” Richardson said. “It’s one of those things where we can all do our part to keep pollution levels down.”

The soaring temperatures also are expected to continue drying grasses, shrubs and trees across the Bay Area and further exacerbate drought conditions that have already reached dire levels across California.

The most recent U.S Drought Monitor’s report, issued Thursday, showed the entire Bay Area — along with 97% of the state — in a severe drought. Of that total, 60% of the state was considered to be in extreme drought — essentially, the entire Central Valley — and 12% was in exceptional drought.

“These warm and dry conditions are going to dry the fuels even further,” said Roger Gass, a National Weather Service forecaster. “Things are already drying out heading to the summer months.”

Source: www.mercurynews.com