The air quality in the Bay Area right now is as bad as Beijing

Maps of the Bay Area from BerkeleyEarth.org, a site tracking air quality around the globed, showed unhealthy levels in many areas on the morning of Oct. 12, 2017. Maps of the Bay Area from BerkeleyEarth.org, a site tracking air quality around the globed, showed unhealthy levels in many areas on the morning of Oct. 12, 2017. Photo: BerkeleyEarth.org Photo: BerkeleyEarth.org Image 1 of / 97 Caption Close The air quality in the Bay Area right now is as bad as Beijing 1 / 97 Back to Gallery

San Franciscans woke up Thursday morning breathing air as polluted as that in Beijing, a city known for its suffocating gray haze.

Some people wore masks as they walked or rode their bikes to work—an uncommon sight in the Bay Area.

"These fires are bringing Beijing to the Bay Area and are allowing us to see what they experience around the clock," says Richard Muller, a UC Berkeley professor of physics who co-founded the site Berkeley Earth, which tracks air quality around the globe with an interactive map.

REVIEW: Best air purifiers for the money

On the morning of Oct. 12, the amount of particulate matter in the area in some parts of San Francisco were in the 151-200 range on the air quality index, matching that in Beijing.

The Bay Area has been choking on wood smoke since Sunday night after wind-stoked fires broke in Napa and Sonoma counties.

On Thursday morning, most of the Bay Area reached an "unhealthy level," prompting schools to keep students inside at recess and forcing some to close entirely.

"We're seeing the worst air quality ever recorded in many parts of the Bay Area," Flannigan told SFGATE earlier this week. "The entire Bay Area population is likely being affected by the smoke."

The movement of smoke is dependent on the weather, said Charles Bell, a forecaster with the National Weather Service. On Thursday morning, light winds from the north pushed smoke into the Bay Area.

"By later today and going into today, the winds are going to die down so that will mean less of the smoke coming down," Bell says. "We might get a little bit of a break early Friday and then late Friday, the winds will pick up again and bring smoke down across the entire region."

Brian Garcia, also a meteorologist with NWS, agreed.

"We're going to see a really strong settling of the smoke in the Bay Area on Friday and Saturday," he said. "Not to mince words. It's going to be really bad. It's not going to be fun."

Muller says when he's looking at air quality around the world on his interactive map, the United States is usually mostly a green color, meaning the air is clean, whereas red is common in other parts of the globe where the the levels of airborne particulate matter are high.

"Air quality is the greatest environmental catastrophe taking place in the world today," Muller says. "And we only notice it on days when a city in China sets a new record, but it's a daily occurrence.

"By published estimates, it's killing 4,400 people a day in China alone. People die prematurely in China every day and we pay no attention. The air quality in the Bay Area right now should alert us that this is real."