Lake Ontario Water Temperature, Tides & Buoy Report

Region: New York / Ontario

Lake Ontario is the smallest Great Lake by surface area but one of the deepest, averaging nearly 300 feet and reaching over 800 — it holds more water than Lake Erie despite covering less than half the area. It sits at the eastern, downstream end of the chain, fed by the Niagara River below Niagara Falls and draining out through the St. Lawrence past the Thousand Islands. Its depth and steep sides make it behave like a cold inland sea: it stratifies hard in summer, rarely freezes over, and holds cold water close to shore.

NOAA Stations Near Lake Ontario

Frequently Asked Questions

What conditions does Big Buoy track on Lake Ontario?
Big Buoy tracks real-time water temperature, wave height, wind speed and direction, and atmospheric pressure from 16 stations across the region, including Lake Ontario West (Niagara & Hamilton), Lake Ontario North (Toronto shore), Lake Ontario East (off Rochester), and Prince Edward Point. You also get solunar tables and extended weather outlooks covering the lake from the Niagara River to the St. Lawrence.
Why does Lake Ontario's water temperature change so fast?
Lake Ontario is deep and stratifies strongly in summer, holding cold water just below the surface. When wind pushes the warm surface layer away from a shore — often a northerly or easterly wind on the south shore — cold water upwells from below and can drop surface temperatures 15–20°F in a matter of hours. That moving temperature break is exactly what the salmon and trout fishery keys on, so checking water temperature at the buoy nearest you before a trip is essential.
What conditions should I check before heading out on Lake Ontario?
Wind direction and speed come first — the long west-to-east fetch lets a sustained westerly or northeasterly build steep seas across the open lake quickly, and the deep water keeps those waves short and steep. Check water temperature at the buoy nearest your area to find the thermocline and upwelling breaks the fishery relies on. If you're in the sheltered Bay of Quinte in the northeast, expect warmer, calmer water than the open lake on the same day. Big Buoy shows real-time data from 16 NOAA stations from Niagara to the St. Lawrence so you can compare the open lake against the bays before heading out.
What NOAA stations does Big Buoy track near Lake Ontario?
Big Buoy tracks 882 NOAA buoys and 3,400+ tide stations nationwide, with many in the Lake Ontario area — including West Lake Ontario - Grimsby (45139), NW Lake Ontario Ajax (45159), EAST Lake Ontario - 20NM North Northeast of Rochester, NY (45012), Prince Edward Pt (45135). Each station reports water temperature, wave height, wind speed and direction, and more — updated every 10 minutes. Open the map to see all stations near Lake Ontario.
What marine conditions are available for Lake Ontario?
Big Buoy shows real-time water temperature, wave height, swell period, wind speed and direction, 7-day tide tables with exact high and low times, and daily solunar peak windows for Lake Ontario.
Is Big Buoy free to use for Lake Ontario marine conditions?
Yes. Real-time buoy data, tides, and solunar for Lake Ontario are completely free with no account required. Big Buoy Pro adds the Wind Tab, the Depth Chart, satellite overlays (sea surface temp, chlorophyll, currents), 16-day forecasts, and forecast model switching.