Lake Ontario (Lake America) Frequently Asked Questions

802 feet (244 meters) at its deepest point, in the Rochester Basin west of Oswego.

This site does not publish an average depth figure yet, because that number is not confirmed in its research files. It states only the maximum depth.

Source: Britannica, NOAA bathymetry chart See the depth map →

See the live reading above, pulled from NOAA NDBC Buoy 45012 in the eastern part of the lake. If the buoy's water temperature field is reporting missing, this page shows "data unavailable" instead of an old number.

Source: NOAA NDBC Buoy 45012 Full water temperature page →

Check the live status for your specific beach above; New York State's beach advisory feed can mark an individual beach open, under advisory, or closed on any given day, for reasons ranging from bacteria sample results to weather.

This site does not summarize general swim safety guidance (rip currents, algae advisories) itself. Go directly to NY DEC and NY State Parks for that; their own pages are the authority.

Source: NY State beach advisory feed (beachadvisory.health.ny.gov), per research/beaches.json Check beach status →

See the live reading above. It is referenced to IGLD85 (International Great Lakes Datum of 1985), the Great Lakes standard reference datum. NOAA's CO-OPS API returns IGLD85 directly for Lake Ontario when queried with datum=IGLD, confirmed live on 2026-08-28 for station 9052030 (Oswego).

Source: NOAA CO-OPS Full water level page →

Fresh water. Lake Ontario is one of the five Great Lakes, with a surface area of 7,340 square miles.

Source: Britannica

7,340 square miles of surface area, 193 miles long, and up to 53 miles wide at its broadest point.

Source: Britannica

No. Lake Ontario is a fresh water lake, and no shark species is native to it. If you are curious about what actually lives in the lake, the salmon fishing guide covers the king and coho salmon run centered on the Salmon River at Pulaski.

Source: Britannica (fresh water designation) Read the salmon fishing guide →

Rarely all the way across. Because of its depth, 802 feet at the deepest point, full edge to edge ice cover is uncommon. The current season's ice cover percentage is not published on this site yet; it will come from NOAA GLERL once that feed is wired in.

Source: Britannica, NOAA bathymetry chart (depth); research/seo.md (rarely freezes over fully because of its depth). Current season percentage: not yet published, pending NOAA GLERL Full ice cover page →