The Bay Area Air Quality Management District has issued a Spare the Air alert for Thursday, Friday and Saturday because of smoke in the region from the Kincade Fire in the North Bay.
The fire, which started Wednesday night in The Geysers area of Sonoma County, has caused evacuations and burned 10,000 acres as of Thursday morning.
Smoke is impacting the North Bay as of Thursday morning and could spread across more of the region later in the day and on Friday, according to the air district.
People who smell or see smoke should stay inside with windows and doors closed, and set air conditioning units and car vent systems to re-circulate so the smoke does not get inside, air district officials said.
The combination of high temperatures across the Bay Area and expected wildfire smoke from the Kincade Fire may cause a simultaneous heat and poor air quality event. Air quality measurements, updated hourly, are available on the air district's monitoring page.
Strong winds from the east are forecast for Saturday evening through Monday morning in the Bay Area even as another major wildfire burns in the region, according to the National Weather Service.
On Thursday evening, PG&E chief meteorologist Scott Strenfel said that the wind event will be the strongest offshore event this season "by a large margin."
Weather officials are forecasting critical fire conditions and that the winds may be the strongest since the ones that fanned the North Bay fires in 2017.
The Spare the Air alerts are the 20th, 21st and 22nd issued by the air district this year.
People can find out when a Spare the Air alert is in effect by visiting sparetheair.org, calling 800-HELP-AIR (4357-247), downloading the Spare the Air smartphone app for iPhone or Android devices or connecting with Spare the Air on Facebook, Twitter or YouTube.