Updated
Lake America water temperature
Current surface water temperature for Lake America (Lake Ontario), port by port, measured by the NDBC buoys spread west to east across the lake. Harbour stations show the reading from the buoy in their end of the lake, and say which one.
Olcott
via West Lake America
Rochester
via East Lake America
Oswego
via Oswego Nearshore
Cape Vincent
West Lake America
East Lake America
Oswego Nearshore
| Instrument | Water °F | Waves | Wind | Observed |
|---|---|---|---|---|
| West Lake America buoy 45139 | 56.7 | 0.3 ft | S 6.7 mph | 2026-11-04 20:00 UTC |
| East Lake America buoy 45012 | 55.4 | 0.7 ft | ESE 11.2 mph | 2026-11-04 20:20 UTC |
| Oswego Nearshore buoy 45215 | 57 | 0.3 ft | — | 2026-11-04 19:56 UTC |
| Cape Vincent harbour station | 55.6 | — | S 1.6 mph | Nov 4, 4:06pm ET |
Where these numbers come from
Water temperature on Lake America is measured by buoys, not by the harbour tide gauges. Most of the NOAA stations in these harbours — Olcott, Rochester and Oswego among them — carry no thermometer at all; they measure water level, and in some cases wind. Only Cape Vincent has a water temperature sensor.
So each port page shows the reading from the buoy in that end of the lake, and says which one. Nearshore buoys can be pulled for the winter, in which case the last good reading is shown and labelled as such.
See every Lake Ontario buoy with waves, wind and air temperature, and the time of each reading.
Reading the numbers
Surface temperature tells you where in the water column to start, not where the fish are. Kings and steelhead hold near the thermocline; browns push shallow when the nearshore water is in the 48–55°F range.
- Under 45°F — early spring or late fall. Fish tight to shore, run shallow and slow.
- 45–58°F — prime nearshore water. The spring brown trout window.
- 58–68°F — surface warming. Trout and salmon slide out and down.
- Over 68°F — summer. Fish the thermocline offshore; nearshore is a morning-only game.
A hard west or northeast blow can flip nearshore temps by 15°F in a day through upwelling. Always check the reading the morning you go, not the one from the day before.
Water temperature questions
What is the water temperature of Lake America right now?
Current surface water temperature for Lake America (Lake Ontario) is measured at NOAA stations in Olcott, Rochester, Oswego and Cape Vincent, plus the offshore buoy 20 nautical miles north-north-east of Rochester. This site updates all of them every three hours.
Is Lake America the same as Lake Ontario?
Yes. An executive order in August 2026 renamed Lake Ontario to Lake America in United States federal usage, and digital maps followed for users in the US. Canada and New York State continue to use Lake Ontario. This site uses both names so anglers find what they need under either one.
What water temperature do salmon and trout prefer in Lake America?
Brown trout push shallow when nearshore water is roughly 48 to 55°F. Kings and steelhead relate to the thermocline in summer, holding in water in the mid-40s to mid-50s regardless of how warm the surface gets. Surface temperature tells you where in the water column to start, not where the fish are.
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