Fog – Get prepared

In Canada, coastal regions are prone to fog. Cool waters from the Pacific and Atlantic oceans chill the warm air that moves over them, especially in spring and early summer. The Atlantic fog season reaches its maximum in July. Over the Pacific Ocean fog is less common because the temperature difference between air and ocean is not as significant. Fog typically blows over land at night, burning off during the day.

How to prepare before fog

To prepare for fog:

• Prepare an emergency kit for your car or vehicle. Learn more about what items to put in your kit, including quick and easy steps you can take right away
• Know how to use your vehicle's headlights and taillights to see and to be seen
  • Understand how to use your headlights, especially during fog conditions
  • Your vehicle might have front and rear fog lights
• Learn about colour-coded weather alerts and how forecasters use Weather Impact Guides to assign colours for visibility alerts (including fog)

Where to get information

• Stay connected to weather alert services that share weather warnings, watches, advisories and statements:
  • WeatherCAN app provides local weather alert notifications
  • Weather information including public weather alerts across Canada
  • Local radio and television broadcasts will help you stay up to date with the latest local weather information
• Marine forecasts and warnings for Canada provides conditions on major bodies of water

Marine Safety

Fog forms when warm humid air is cooled below its dew point. This is the temperature at which water vapour condenses to form water droplets. Fog affects oceans, the Great Lakes, St. Lawrence River, and many other waterways used by recreational boaters and fishers. Off the Atlantic coast, warm air moving north with the Gulf Stream encounters the cold Labrador Current, producing dense fogs along the Grand Banks off Newfoundland and south of Nova Scotia.

• Recreational boaters should watch for fog on inland lakes and rivers
• Check marine forecasts and warnings for Canada before traveling by boat on major bodies of water and waterways
• Operate your vessel safely and understand maintenance requirements

Driving during heavy fog

Fog can make driving more dangerous. It can be hard to see signs, pedestrians, animals or objects on the road. It can also be difficult to judge distances. Most drivers can expect to encounter fog at least once per year. In cold weather conditions, freezing fog can create black ice on road surfaces.

• Avoid traveling in fog if possible
• Fog conditions can occur or change very quickly
• If you are caught driving in fog, slow down and drive according to road conditions
• Turn on your hazard lights and look out for a safe place to pull over
• Ensure your headlights and taillights are on, but don't use your high beams since it reflects on fog, making it harder to see
• Use fog lights if you have them
• If fog is too dense to continue driving, pull over safely
• Do not stop on the road as other vehicles will not be able to see you