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Cornwall to Montréal

Forecast

Marine Forecast

Issued 10:08 AM EDT 28 July 2026

Today Tonight and Wednesday.

Wind light with gusts to 45 knots near thunderstorms today and early this evening. Wind light Wednesday.

Showers. Risk of thunderstorms this afternoon and this evening. Visibility as low as 1 mile in showers.

Extended Forecast

Issued 06:00 AM EDT 28 July 2026
Thursday Wind northeast 10 to 15 knots.
Friday Wind light.
Saturday Wind light.

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Weather Conditions

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

There is no ice forecast issued for this area.

Warnings

Watches (In effect)

Squall watch in effect

Cornwall to Montréal

Issued 10:04 AM EDT 28 July 2026 This afternoon and this evening, conditions will be favourable for the development of squalls with wind gusts up to 45 knots, frequent lightning, hail and poor to very poor visibility due to showers at times heavy.

Proceed with caution as visibility may suddenly be reduced to near-zero. Vessels without lightning protection should make their way to shore immediately. 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 28 July 2026 Today Tonight and Wednesday At 3:00 a.m. EDT today trough located from Lake Michigan to
Labrador.
By 8:00 p.m. EDT Wednesday quasi-stationary trough located over
Montréal to Sept-Îles.

Great Lakes - Lake Erie and Lake Ontario Area

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