Marine Forecasts

• Niagara River to Hamlin Beach
• Hamlin Beach to Sodus Bay
• Sodus Bay to Mexico Bay
• Mexico Bay to St. Lawrence River

• This Afternoon
  Southwest winds 5 to 10 knots becoming west. Sunny. Waves 1 foot or less.
• Tonight
  South winds 5 to 10 knots increasing to 15 to 20 knots. Mostly cloudy. Waves 1 foot or less building to 2 to 4 feet.
• Tuesday
  South winds 15 to 20 knots. Showers likely in the morning, then showers with a chance of thunderstorms in the afternoon. Waves 2 to 4 feet subsiding to 1 to 3 feet.
• Tuesday Night
  South winds 10 to 15 knots becoming west 15 to 20 knots. Showers with a chance of thunderstorms. Waves 1 to 3 feet building to 3 to 5 feet. Waves occasionally around 6 feet.
• Wednesday
  West winds 15 to 25 knots diminishing to 10 to 15 knots. Showers during the day. Waves 5 to 8 feet subsiding to 3 to 5 feet. Waves occasionally around 10 feet.
• Thursday
  West winds 5 to 10 knots becoming southwest. Mainly clear. Waves 1 to 3 feet subsiding to 1 foot or less.
• Friday
  South winds 10 knots or less. Mainly clear, then becoming partly cloudy. Waves 1 foot or less.

Open Lake Forecast for Lake Ontario
National Weather Service Buffalo NY
1001 AM EDT Mon Jul 20 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 30.0 inch area of high pressure will build across the Great Lakes 
today, followed by a warm front crossing the lake tonight and 
another cold front Tuesday night, with these fronts attached to a 
29.4 inch area of low pressure near James Bay. A secondary cold 
front will cross the lake Wednesday, with a 30.1 inch high building 
across the lower Great Lakes region Wednesday night through Friday.

LOZ062-202100-
Lake Ontario open waters from the Niagara River to Hamlin Beach-
1001 AM EDT Mon Jul 20 2026

.THIS AFTERNOON...Southwest winds 10 knots or less becoming
southeast. Waves 1 foot or less. 
.TONIGHT...Southeast winds 5 to 15 knots becoming south. Waves
2 feet or less. 
.TUESDAY...South winds 15 to 20 knots becoming southwest. Showers
with a chance of thunderstorms. Waves 1 to 3 feet building to
3 to 5 feet, then subsiding to 2 to 4 feet. 
.TUESDAY NIGHT...Southwest winds 15 to 20 knots becoming west.
Showers with a chance of thunderstorms in the evening, then a
chance of showers overnight. Waves 2 to 4 feet building to 3 to
6 feet. 
.WEDNESDAY...West winds 15 to 25 knots becoming northwest and
diminishing to 10 to 15 knots. Waves 4 to 7 feet subsiding to
2 to 4 feet. Waves occasionally around 9 feet. 
.THURSDAY...West winds 5 to 10 knots becoming southwest. Waves
2 feet or less. 
.FRIDAY...Southwest winds 10 knots or less. Waves 1 foot or less.

Winds and waves higher in and near thunderstorms.

$$

LOZ063>065-202100-
Lake Ontario open waters from Hamlin Beach to the Saint Lawrence
River-
1001 AM EDT Mon Jul 20 2026

.THIS AFTERNOON...Southwest winds 5 to 10 knots becoming
northeast. Waves 1 foot or less. 
.TONIGHT...East winds 5 to 15 knots becoming south 15 to
20 knots. Waves 1 foot or less building to 2 to 4 feet. 
.TUESDAY...South winds 15 to 20 knots. Showers with a chance of
thunderstorms. Waves 3 to 5 feet subsiding to 2 to 4 feet. 
.TUESDAY NIGHT...Southwest winds 10 to 15 knots becoming west
15 to 20 knots. Showers with a chance of thunderstorms. Waves
1 to 3 feet building to 3 to 6 feet. 
.WEDNESDAY...West winds 15 to 25 knots. Showers likely during the
day. Waves 5 to 8 feet subsiding to 3 to 5 feet. Waves
occasionally around 10 feet. 
.THURSDAY...West winds 5 to 15 knots becoming southwest. Waves
1 to 3 feet subsiding to 1 foot or less. 
.FRIDAY...Southwest winds 10 knots or less becoming south. Waves
1 foot or less. 

Winds and waves higher in and near thunderstorms.

$$

LOZ061-202100-
MAFOR 2015/
ONTARIO WEST 1/2 11600 11200 12300 11400 12410 11420. A chance of
showers Tuesday morning. Waves 2 feet or less this afternoon and
tonight. Waves 1 to 3 feet building to 2 to 4 feet Tuesday
morning. 

ONTARIO EAST 1/2 11500 12100 11200 11410 13420. A chance of
showers Tuesday morning. Waves 1 foot or less this afternoon.
Waves 1 foot or less building to 2 to 4 feet tonight. Waves 3 to
5 feet Tuesday morning. 

$$