(AP) — Fog is delaying flights by about an hour in Denver, and some smaller planes are being diverted to other airports because of the low visibility.

The fog is expected to lift by 9 a.m. Monday.

About 15 commuter flights headed to Denver International Airport have had to instead land in Colorado Springs, Durango and Eagle, as well as to Albuquerque, N.M., and Rapid City, S.D.

Fog is unusual in Denver, which boasts of having more than 300 sunny days a year.