Passengers at San Francisco International Airport should expect average delays of more than 45 minutes this morning due to heavy fog, according to airport officials.

There will be average delays of 48 minutes at SFO due to a low ceiling of fog and will mostly affect planes coming from Denver or farther west, airport officials said.

A ground-delay program will be in effect at SFO today from 8:30 a.m. to 2 p.m.