Language selection

Government of Canada / Gouvernement du Canada

Search

Weather shortcuts

Cornwall to Montréal

Warnings

Forecast

Marine Forecast

Issued 03:00 AM EDT 12 August 2026

Today Tonight and Thursday.

Wind light becoming west 10 to 15 knots near noon then becoming light this evening. Wind becoming west 15 Thursday morning then diminishing to light Thursday evening.

Scattered showers this afternoon and this evening with a risk of thunderstorms. Scattered showers Thursday late in the day.

Extended Forecast

Issued 06:00 AM EDT 12 August 2026
Friday Wind light becoming northwest 10 to 15 knots in the morning.
Saturday Wind light.
Sunday Wind light.

Stay connected

ATOM

List of Official Text Forecasts
Resources

Weather Conditions

Skip Image

Zoom-in to make a selection

Map of Great Lakes - Lake Huron marine weather areas Erieau CFB Trenton Muskoka Airport Parry Sound Harbour Toronto City Centre Airport Lake Simcoe Regional Airport Wiarton Airport Point Petre Lagoon City Western Islands Cobourg Port Colborne Windsor Airport Point Pelee Welland-Pelham Vineland Station Burlington Lift Bridge Southeast Shoal St. Catharines / Niagara District Airport Goderich Port Weller Long Point Harrow AAFC Hamilton Munro Int'l Airport Tobermory Sarnia Chris Hadfield Airport Oshawa Executive Airport Collingwood Port Stanley - 45132 Prince Edward Point - 45135 Georgian Bay - 45137 Grimsby - 45139 Port Colborne - 45142 South Georgian Bay - 45143 Lake St Clair - 45147 South Lake Huron - 45149 Lake Simcoe - 45151 Lake Nipissing - 45152 North Channel - 45154 Ajax - 45159 Sault Ste. Marie Airport Killarney Greater Sudbury Airport North Bay Airport Gore Bay-Manitoulin Airport Peterborough Municipal Airport Brockville Grenadier Island Kingston Airport
Legend:
buoy Buoy
land station Land Station
Ice Conditions

There is no ice forecast issued for this area.

Warnings

Watches (In effect)

Squall watch in effect

Cornwall to Montréal

Issued 1:27 PM EDT 12 August 2026 Conditions are favourable for the development of squalls with wind gusts up to 35 knots.



Mariners are advised to prepare for potential squalls. Vulnerable vessels are most at risk and should seek safe harbour if underway. Consider delaying or postponing travel in areas under the Squall Watch.

Please continue to monitor alerts and forecasts issued by Environment Canada. For more information monitor Canadian Coast Guard radio or Weatheradio stations.

Synopsis

Technical Marine Synopsis

Issued 3:00 AM EDT 12 August 2026 Today Tonight and Thursday At 3:00 a.m. EDT today low 999 mb located over the Gulf of
St. Lawrence.
By 8:00 p.m. EDT tonight departing low 998 mb located over northern
Newfoundland.

At 8:00 p.m. EDT Thursday trough located from Labrador to Sept-Îles.

At 8:00 p.m. EDT Thursday approaching ridge located over
northwestern Ontario.

Great Lakes - Lake Huron Area

Another Region

Marine Weather for Canada

Weather shortcuts


How to use
  • Add to shortcuts
    • Go to the desired page on the site, open the Weather shortcuts menu and click on the "Add to shortcuts" button
    • Page name will display in the "Add this page" window, the name can be changed by highlighting the text and entering the desired name
    • Click on the "Save" button to add the link to the list
    • Click on the "X" button to close the panel
  • Delete a link
    • Click on the "Organize shortcuts" button
    • Select the link to delete
    • Click on the "Delete" button to remove the link from the list
    • Click on the "Close" button to save the change
  • Move a link up/down the list
    • Click on the "Organize shortcuts" button
    • Click and hold the link and move to new location in the list
    • Click on the "Close" button to save the change
  • Rename a link
    • Click on the "Organize shortcuts" button
    • Select the link to rename
    • Click on the "Rename" button and change the link name
    • Click the enter or tab key
    • Click on the "Close" button to save the change
  • Keyboard navigation
    • Use the Tab key to move to a button or link
    • Use the Enter key to click on buttons or links
    • Organize shortcuts navigation
      • Use the ↑ Up key to select the link above. If none are selected, it will select the first link.
      • Use the ↓ Down key to select the link below. If none are selected, it will select the last link.
      • Use the Page Up key to move a selection up in the list.
      • Use the Page Down key to move a selection down in the list.
  • Restore default list

    Warning: Clicking on the button below will remove all your customized links.

Customized Weather shortcuts

Save your customized list as a bookmark.

Copy/paste or click on the link below then when the page displays, you can bookmark the page using the web browser. Bookmarking your customized list will allow you to access it even if the local storage on your device is erased.

Features

Colour-coded weather alerts

Learn more about weather alerting in Canada

Thunderstorm Outlooks

Find the Thunderstorm Outlook for your area.

Feedbackabout this web site
Date modified: