The Bay Area Air Quality Management District has issued another Winter Spare the Air alert for Wednesday.
It will be the sixth in a row and the 12th so far in the season that runs from Nov. 1 through Feb. 28, air district officials said.
"We continue to see a really persistent weather pattern across the Bay Area right now that is making for calm winds and no rain moving into the area," air district spokesman Tom Flannigan said.
"It's a combination that means worsening air pollution for the region," Flannigan said.
Burning wood or other solid fuels is prohibited on Spare the Air days, but Flannigan said people living in homes that do not have an installed source of heat may be able to apply to the district for an exemption if they rely on a wood stove or fireplace to heat their homes.
Penalties for violating the prohibition on burning wood or other fuels include a $100 fine, although first-time offenders may also have the option of attending a wood smoke awareness class in lieu of paying the fine.
Fines for second and subsequent offenses start at $500.
The Bay Area Air Quality Management District forecasts upcoming weather conditions each day. Information about Thursday's status will be available early Wednesday afternoon.