Language selection

Weather shortcuts

Eastern Lake Ontario

Forecast

Marine Forecast

Issued 06:30 PM EDT 21 June 2025

Tonight and Sunday.

Strong wind warning in effect.

Wind southeast 10 knots increasing to south 15 this evening and to southwest 20 late overnight. Wind diminishing to southwest 15 near noon Sunday.

Scattered showers this evening. Scattered showers overnight and Sunday morning with a risk of thunderstorms.

Waves

Issued 06:30 PM EDT 21 June 2025
Tonight and Sunday. Waves 0.5 metres or less building to 0.5 to 1 near midnight and to 1 to 1.5 early Sunday morning. Waves subsiding to 0.5 to 1 Sunday afternoon.

Extended Forecast

Issued 06:30 PM EDT 21 June 2025
Monday Wind southwest 15 knots.
Tuesday Wind west 15 knots diminishing to light late in the day.
Wednesday Wind light.

Stay connected

ATOM

Weather Conditions

Skip Image

Zoom-in to make a selection

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

*Ice Forecast and Warnings also apply to U.S. waters

Ice Forecasts

Issued 12:00 PM EDT 16 May 2025 Forecasts have ended for the season.
Warnings

Warnings (In effect)

Strong wind warning in effect

Eastern Lake Ontario

Issued 6:30 PM EDT 21 June 2025

'Strong' winds of 20 to 33 knots are occurring or expected to occur in this marine area. Please refer to the latest marine forecasts for further details and continue to monitor the situation through Canadian Coast Guard radio or Weatheradio stations.

Watches (In effect)

Squall watch in effect

Eastern Lake Ontario

Issued 00:46 AM EDT 22 June 2025 Conditions are favourable for the development of squalls with wind gusts up to 50 knots, frequent lightning and hail.

An area of thunderstorms over central Ontario will move southeastward through early this morning.

Mariners are advised to prepare for potential squalls. Vulnerable vessels are most at risk and should seek safe harbour if underway.

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 6:30 PM EDT 21 June 2025 Tonight and Sunday At 6:30 p.m. EDT tonight departing low 1000 mb located near
James Bay.

At 6:30 p.m. EDT tonight low 996 mb located over South Dakota.
By 6:30 p.m. EDT Sunday low 996 mb located over western North
Dakota.

Great Lakes - Lake Erie and Lake Ontario Area

Another Region

Date modified: