Smoke from wildfires is causing airline flights to be delayed or canceled in Northern California.
More than 103 flights were canceled by Thursday afternoon at San Francisco International Airport, said airport spokesman Doug Yakel.
He says delays on other flights averaged 75 to 90 minutes. The Federal Aviation Administration says some arriving flights are delayed more than three hours.
Several flights are canceled at Charles M. Schulz Sonoma County Airport in Santa Rosa, near the epicenter of wildfires in wine country. Airport director Jon Stout said United and Alaska each are planning a flight later, and a Sun Country flight is expected if smoke is not too bad.
By Thursday night the still-raging wildfires had killed at least 31 people and destroyed more than 3,500 homes and businesses north of San Francisco.