Smoky Scent Blamed on Sonoma

The hazy skies in the Bay Area on Thursday are nothing to worry about, fire officials said.

The north winds are blowing smoke into much of the Bay Area from several fires burning in Northern California, according to Cal Fire spokesman Daniel Berlant.

Much of the smoke comes from the Yellow Fire, a 125-acre wildland blaze in Sonoma County. The fire sparked early Wednesday northwest of Calistoga in Knights Valley. It was 50 percent contained by Wednesday night and was expected to be fully contained sometime Thursday, according to the California Fire News blog.

Three other wildland fires burned in Napa County this week.

• The Silverado Fire in Napa County charred about 75 acres of grass and oak woodland north of Yountville and has destroyed one structure. It started late Tuesday and has been contained.
• A blaze, dubbed the Summit Fire, burned about 2 acres near the Schramsberg Vineyards south of Calistoga.
• A third fire broke out Wednesday night off Soda Canyon Road, not far from where a major blaze burned in 2012.

In Marin County, the Ross Valley Fire Department took to Facebook to try to ease residents' concerns about the smoke Thursday.

"There are no fires burning in Marin County," the agency posted. "If you see a lot of smoke or flames, call 9-1-1 and provide the dispatcher with as much information as possible."

The Centers Control and Prevention shared this fact sheet about health threats from wildfire smoke.