Timelapse video from Atlas Peak in Napa shows a thick blanket of smoke rolling into the Bay Area on Thursday.
VIDEO: Smoke from Camp Fire in Butte County fills air in Bay Area
In the East Bay, the sun setting through all the haze created a dark orange glow.
"If you do smell smoke, you are being impacted," said Walter Wallace with the Bay Area Air Quality Management District. An air quality advisory is in effect until at least Friday.
"Young kids tend to breathe a lot more than adults, so in that case they're going to be breathing in a lot more of the air that could be harmful," Wallace said.
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Schools in Oakland, public and private, from day care through high school, decided to keep students inside Thursday afternoon because of the poor air quality.
"It smelled like the other times that the California wildfires happened," said Will Lecocq, a freshman at Bishop O'Dowd High School in Oakland.
Because of the smoke, he said school officials made an announcement at lunch that everyone had to stay inside for the rest of the day.
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"Kids were like getting water constantly because the smoke was hurting their throat," Lecocq said. His mother, Candes Lecocq, said she didn't realize there was a fire burning until she left her office in San Francisco Thursday afternoon and saw and smelled the smoke in the air.
She said she's concerned about the extended fire season in California and the poor air: "I worry about it all the time, especially with the kids and how it impacts them and their breathing."
Many people in downtown Oakland were wearing surgical masks to protect themselves from the smoke, including one young woman who said the poor air exacerbates her breathing problems due to sleep apnea.
"The smoke is really bad for my health," she said.
It's important to note that the only type of masks that protect your lungs from wildfire smoke are N95 respirator masks. You can find them online and at many hardware stores.