Bay Area Air quality regulators are issuing the fifth Spare the Air alert of the season for Sunday.
The alert means the burning of wood, manufactured logs and solid fuel is prohibited outside and indoors as well, other than households that have only woodstoves or fireplaces for heat.
Cold weather accompanied by a high pressure system is expected to cover the Bay Area Sunday, trapping wood smoke close to the ground and allowing fine particulate pollution to rise to unhealthy levels.
"It's important that Bay Area residents do their part to protect their families and neighbors by not lighting up their fireplaces and wood stoves," Jack Broadbent, executive officer of the Bay Area Air Quality Management District said in a statement.
"Wood smoke is the 'other second-hand smoke' — it's hazardous like cigarette smoke but has broader public health impacts when it builds up in our communities on cold, still days and nights," he said.