A fog advisory has been issued for Waterloo region and Guelph Thursday morning.

It comes after snow, freezing rain and cold temperatures on Wednesday gave way to rain and milder temperatures overnight.

Environment Canada issued a fog advisory that says thick fog is expected throughout the morning commute. 

Drivers have been warned that visibility may be significantly and suddenly reduced to near zero. Environment Canada says drivers should exercise caution on the roads this morning. 

"The freezing …