Environment Canada has warned of dense fog in Durham Region which is likely to result in zero visibility in parts.
In an advisory issued at 8:20 pm last night, it said widespread areas of fog are developing this evening. Dense fog with near zero visibilities are likely.
Conditions will improve through Wednesday morning.
Travel is expected to be hazardous due to reduced visibility. If visibility is reduced while driving, slow down, watch for tail lights ahead and be prepared to stop.