A Spare the Air Alert has been issued for Sunday due to concerns about smog, according to the Bay Area Air Quality Management District, and officials are asking the public to refrain from driving.
District officials say that nearly 40 percent of smog in the Bay Area is caused by passenger vehicles, and the most effective way for residents to reduce smog pollution is by driving less.
Vehicle exhaust combined with a high-pressure system bringing clear skies, inland temperatures over 100 degrees, light morning winds and a week afternoon sea breeze, are expected to create unhealthy levels of air pollution Sunday.
"The primary thing we're looking at is high levels of ozone," district spokesman Ralph Borrmann said.
Sunday's alert is not connected to the smokey skies reported throughout the Bay Area as a result of wildfires in Lake County, according to Borrmann.
"The fire is a separate factor, and it's not actually affecting air quality," Borrmann said.
He called it counterintuitive, saying that while many Bay Area residents can smell the smoke - the particulate mass associated with that smoke is suspended in the air column at a higher altitude.
This is the third Spare the Air Alert for smog so far this year, according to district officials.