The problems extend into the South Bay, KRON 4 reports, as the County of Santa Clara Public Health Department has issued a health advisory warning residents to stay indoors.
Residents in the North Bay are experiencing the brunt of the pollution because of nearby wildfires in California's wine country. Usually the Bay Area benefits from a natural air conditioning system with winds blowing in off the coast and carrying the air inland. Other suggestions include staying indoors with windows and doors closed as much as possible and shutting off fans that bring smokey outdoor air inside.
The smell of fire hangs in the air in San Francisco.
"I kind of have a sore throat today", said Erik Loboschefsky of Sacramento. 80 flights were cancelled as of Tuesday night, at the request of the Federal Aviation Administration, which put the airport on "a delay program, which slows the pace of arriving flights to provide greater separation between aircraft" due to visibility issues related to the smoke.
"It's an unprecedented level of smoke", said Lisa Fasano of the Bay Area Quality Management District.
The worst hour so far was measured on Tuesday in Napa, Calif., with an air quality index of 404 for small particulate matter - so high it's off the chart, as you can see below.
"Air quality has improved throughout the Bay Area, which is wonderful". "But it's expected to get worse as the wind shifts". That's good for putting out the fire. Residents affected by heavy smoke must seek shelter in buildings with filtered air or move to areas outside the region which has been affected by wildfire smoke. Only 20-pack boxes are left with a new shipment coming in.
A series of deadly California wildfires have burned through some 170,000 acres statewide, but heavy smoke from the disaster zones drifted farther still as pesky particles of dust, ash and soot entered the lungs of residents almost 100 miles away.
People with existing respiratory conditions, young children and elderly people are especially susceptible to these pollutants.