San Francisco International Airport says nearly 200 flights have been delayed because of low visibility and smoke caused by wildfires in Northern California.
Airport spokesman Doug Yakel said that as of noon on Friday about 15 percent, or 195 flights, have had delays averaging 45 minutes.
On Thursday, about 500 were delayed, representing about 40 percent of the airport's flights. The airport averages about 1,250 flights per day.
Yakel said smoke was the main factor in low visibility conditions, with visibility at about 1.5 miles Friday compared to 10 miles on a normal day.
The airport is urging travelers to check with their airlines or the airport's website for their flights' status.
Schools across the San Francisco Bay Area were closed Friday as winds carried smoke from wildfires in Northern California that blanketed towns and cities hundreds of miles away.
