A view of the Berkeley HIlls, obscured by smoke and crisscrossed by wires
A view of the Berkeley Hills, obscured by smoke, as seen from the corner of Alcatraz and Shattuck avenues on Tuesday, Sept. 19, 2023. Credit: Ximena Natera, Berkeleyside/CatchLight

Editor’s note: This story was first published 5 p.m. Tuesday and last updated 11 a.m. Wednesday.

Wildfires are again turning skies in Berkeley smoky Tuesday, with a stifling smell in the air and the view of the hills hazy from the flats. 

Fires ripping through Northern California and Oregon brought air quality in Berkeley to unhealthy levels and prompted the Bay Area Air Quality Management District to issue a “Spare the Air” alert through Friday.

The BAAQMD’s official air quality station in Berkeley has been down since June 6, but the district’s sensors in Oakland registered AQIs in the 102 to 120 range Tuesday. Many unofficial PurpleAir sensors in Berkeley registered AQIs above 150 — the benchmark for air that is unhealthy to the general public. 

In the Coast and Central Bay zone, which encompasses Berkeley, BAAQMD forecasts show that the air quality will remain in the “unhealthy for sensitive groups” range — between 101 and 150 — through Thursday and in the moderate range through Saturday.

Screenshot of AirNow map shows that purpleair sensors across Berkeley, Oakland and Albany have registered unhealthy air quality as of Tuesday afternoon.
The AirNow map showed red AQI sensors — a level indicating unhealthy air for some members of the general population — throughout the city around 9 a.m. Wednesday. Credit: AirNow

The BAAQMD recommends you stay inside with windows and doors closed until smoke levels subside.

“Smoke can irritate the eyes and airways, causing coughing, a scratchy throat and irritated sinuses,” the BAAQMD wrote in its air quality advisory. “Elevated particulate matter in the air can trigger wheezing in those who suffer from asthma, emphysema or COPD.”

Being indoors is the best way to limit exposure to wildfire smoke, but if you must go outside, a tight-fitting N95 or P100 can filter out ash and miniscule smoke particles, according to a fact sheet from the U.S. Environmental Protection Agency. (Do not choose a mask with only one strap or two straps that go around your ears, as they are not designed to seal tightly to the face and will not protect your lungs.)

The burning of wood or other solid fuel is banned while the “Spare the Air” alert is in place, and Bay Area residents are asked to limit driving if possible. If you must drive, set your air conditioning units and car vent systems to re-circulate to prevent outside air from moving inside. 

The fires at the Northern California-Oregon border were sparked by lightning strikes in mid-August, according to the U.S. Forest Service. The National Weather Service’s Bay Area office has issued a fire weather watch farther north, but a red flag warning is not currently in place in Berkeley because it is not “critically dry.”

The Berkeley Police Department put out a Nixle Tuesday about the smoky air and asked people not to “call 911 to report the smell of smoke, unless you see direct flames or a plume of smoke.”

Berkeley Unified Superintendent Enikia Ford Morthel wrote an email Wednesday morning telling parents that the district was monitoring air quality and “BUSD schools can stay open during most instances when smoke from wildfires is present in the East Bay.”

“All classrooms are equipped with a MERV 17 HEPA Air Purification Unit that functions effectively with windows opened or closed,” she wrote. “Additionally, filter upgrade work for poor air quality index levels has been completed on existing HVAC systems to include MERV 13 filtration.”

The district’s air quality index response plan states: “At AQI levels between 151-200, classroom windows will be closed and students will eat and exercise during the school day indoors. Coaches will either move practices indoors or reduce vigorous exercise to 30 minutes. Schools will select the largest available indoor space(s) for lunch. During smoke or air quality events, Berkeley High School will have to remain an open campus at lunch time because of facilities constraints.”

Correction: A previous version of this story stated that the BAAQMD’s official air quality station in Berkeley has been down since October 2021, when it was vandalized. It was fixed as of this January, but went off-line again in June.

Iris Kwok covers the environment for Berkeleyside through a partnership with Report for America. A former music journalist, her work has appeared in the San Francisco Chronicle, KQED, San Francisco Examiner...