FZUS61 KBUF 010210 GLFLO Open Lake Forecast for Lake Ontario National Weather Service Buffalo NY 1009 PM EDT Tue Mar 31 2026 For waters beyond five nautical miles of shore on Lake Ontario Waves are the significant wave height - the average of the highest 1/3 of the wave spectrum. Occasional wave height is the average of the highest 1/10 of the wave spectrum. .SYNOPSIS...A 29.6 inch low will move across southern Ontario province this evening before reaching the Canadian Maritimes Wednesday, with a trailing cold front moving south across the lake tonight. A 30.6 inch high will then build east across Ontario and Quebec Wednesday through Thursday. A 29.6 inch low is then forecast to move into the central Great Lakes Thursday night before reaching southern Quebec late Friday. LOZ062-010900- Lake Ontario open waters from the Niagara River to Hamlin Beach- 1010 PM EDT Tue Mar 31 2026 .REST OF TONIGHT...Southwest winds 10 to 15 knots becoming northwest. Rain showers with a chance of thunderstorms late this evening, then a chance of rain showers after midnight. Some thunderstorms may produce gusty winds late this evening. Waves 1 to 2 feet. .WEDNESDAY...Northwest winds 5 to 10 knots becoming northeast. Waves 2 feet or less. .WEDNESDAY NIGHT...East winds 5 to 15 knots increasing to 15 to 20 knots. A chance of rain showers overnight. Waves 2 feet or less building to 3 to 5 feet. .THURSDAY...East winds 15 to 25 knots. Rain showers likely. Waves 4 to 7 feet. Waves occasionally around 9 feet. .THURSDAY NIGHT...East winds 15 to 20 knots becoming south. Rain showers likely. Waves 3 to 6 feet. .FRIDAY...Southwest winds 15 to 25 knots becoming north and diminishing to around 10 knots. Showers likely during the day, then a chance of showers Friday night. Waves 3 to 6 feet subsiding to 2 to 4 feet. .SATURDAY...East winds 15 to 25 knots becoming southwest. Showers. Waves 2 to 4 feet building to 3 to 6 feet. .SUNDAY...West winds 20 to 25 knots becoming northwest. Rain showers likely during the day, then a chance of rain showers Sunday night. Waves 5 to 8 feet. Waves occasionally around 10 feet. Winds and waves higher in and near thunderstorms. $$ LOZ063>065-010900- Lake Ontario open waters from Hamlin Beach to the Saint Lawrence River- 1010 PM EDT Tue Mar 31 2026 .REST OF TONIGHT...West winds 5 to 15 knots becoming northwest. Patchy fog late this evening. Rain showers with a chance of thunderstorms late this evening, then rain showers likely with a chance of thunderstorms after midnight. A chance of rain showers late. Some thunderstorms may produce gusty winds. Waves 2 feet or less. .WEDNESDAY...Northwest winds 5 to 15 knots becoming north. Waves 2 feet or less. .WEDNESDAY NIGHT...Northeast winds 5 to 15 knots increasing to 15 to 20 knots. A chance of rain showers overnight. Waves 1 to 3 feet building to 2 to 4 feet. .THURSDAY...Northeast winds 15 to 20 knots becoming east. Rain showers likely. Waves 3 to 5 feet. .THURSDAY NIGHT...East winds 15 to 25 knots becoming south to 30 knots. Showers likely. Waves 3 to 5 feet building to 5 to 8 feet. Waves occasionally around 10 feet. .FRIDAY...South winds to 30 knots becoming northwest and diminishing to 10 to 15 knots. Rain showers likely during the day, then a chance of rain showers Friday night. Waves 4 to 7 feet subsiding to 2 to 4 feet. Waves occasionally around 9 feet. .SATURDAY...Northeast winds 10 to 15 knots becoming southwest and increasing to 15 to 25 knots. A chance of rain showers during the day, then rain showers Saturday night. Waves 1 to 3 feet building to 3 to 6 feet. .SUNDAY...Southwest winds to 30 knots becoming northwest. Rain showers during the day, then a chance of rain showers Sunday night. Waves 5 to 8 feet building to 7 to 10 feet. Waves occasionally around 13 feet. Winds and waves higher in and near thunderstorms. $$ LOZ061-010900- MAFOR 0103/ ONTARIO WEST 1/2 11610 12710 12700 11800 11200 11110. A chance of rain showers and thunderstorms late this evening, then a chance of rain showers overnight. Waves 2 feet or less. ONTARIO EAST 1/2 11616 12710 12700 11800 12100. A chance of thunderstorms overnight. Waves 2 feet or less. $$