Layers of smoke have been wafting into the region over the past few days from nearby fires, specifically those burning north of the region, including the North Complex Fire east of Chico, the August Complex Fire in the Mendocino National Forest, and even as far as southern Oregon.
"This is an unprecedented scenario in the Bay Area," Garcia said. "We have seen worse air quality, but the duration of unhealthy air quality is something we have not seen before in recorded history around the Bay Area."
Garcia said it's important that people take the unhealthy air warnings seriously, and make sure to "take care of themselves and take care of each other."
On Tuesday and Wednesday, layers of smoke aloft, and marine layer fog below it, caused Bay Area skies to appear orange and dark. The phenomenon made news headlines across the globe.
Smoggy conditions will persist until the region sees enough wind to scour out the atmosphere, which we may not see until early next week, according to Garcia.
He said the smoke cover and lower temperatures are preventing a sea breeze we'd normally get from the Pacific Ocean.
"So we are not expecting the types of winds that we would typically get in our area today or tomorrow," Garcia said.
The National Weather Service says smoke is expected to begin dispersing by Sunday, but especially on Monday.
The several consecutive days of extremely poor air quality has local officials concerned about public health effects, and are warning residents to stay indoors.
Muir Woods, Alcatraz Island and Fort Point are among the outdoor spaces closed Friday due to poor air quality.
In response, San Francisco opened up several weather relief centers for those who cannot shelter indoors, and Muni buses are free Friday to make traveling to those sites easier.