A fog advisory for areas south and east of Calgary has now been expanded north of the city.
The advisory for zero visibility and freezing drizzle now includes Red Deer, Ponoka, Innisfail and Stettler.
The early advisory for Strathmore, Drumheller, Hanna, Three Hills, Vulcan, Lethbridge, Brooks, Medicine Hat, Taber, Milk River and Cypress Hills Provincial Park remains in effect.
The expanded advisory includes the cities of Red Deer and Edmonton.
The fog is expected to lift during the day, but until then freezing drizzle could make driving hazardous due to slippery sections.
A fog advisory for Calgary was lifted early Monday morning.