MINNEAPOLIS (AP) - Thick fog enveloped much of Minnesota and canceled Gov. Mark Dayton's air travel to a water quality forum.

The National Weather Service has issued a dense fog advisory Monday for more than two dozen counties, primarily in the southern half of the state. Visibility is down to a quarter of a mile or less.

Dayton's office says the governor is unable to fly into Luverne. His visit there and his attendance at the forum in Edgerton will be rescheduled.