Environment Canada ends fog advisory for the Barrie, Orillia and Midland area.
The weather agency warned that visibility may be significantly and suddenly reduced to near-zero in some areas.
The fog is expected to dissipate later Thursday morning.
Communities impacted include:
- Barrie – Collingwood – Hillsdale
- Midland – Coldwater – Orr Lake
- Orillia – Lagoon City – Washago
Travel is expected to be hazardous due to reduced visibility in some locations, the weather agency warns.
Drivers are advised to slow down, watch for tail lights ahead and be prepared to stop.