Lake Ontario water temperature

Lake Ontario, Prince Edward Pt · Lake

The current water temperature at Lake Ontario is 21.7 °C (as of September 1, 2026, source: NOAA NDBC).

Lakes stratify in summer: bathing-warm on top, markedly colder a few metres down. Measurements are taken at the surface — right where you swim.

21.7 °C

Measured: September 1, 2026 · continuously updated

💧 Water 21.7° · ☀️ Air 22.2° · high today 23.6°

Temperature trend of recent weeks

Measurement series & statistics

This measurement series includes 1202 data points since July 4, 2026.

Lowest recorded value: 15.0 °C on July 17, 2026 · highest value: 26.9 °C on July 10, 2026.

Nearby waters

Lake Ontario, Oswego · 42.8 km away22.2 °C Lake Ontario, Oswego, NY (274) · 44.6 km away22.4 °C Atlantic, 20NM North Northeast of Rochester, NY · 46.2 km away21.2 °C Lake Ontario, Sodus Point Nearshore Monitoring · 55.9 km away23.0 °C Lake Ontario, Sodus Point, NY · 57.0 km away21.3 °C

More measuring points: Lake Ontario

Sodus Point Nearshore Monitoring23.0 °C Oswego, NY (274)22.4 °C Cape Vincent22.3 °C Oswego22.2 °C Grimsby21.7 °C Sodus Point, NY21.3 °C

Frequently asked questions

Can you swim at Lake Ontario right now?
The current water temperature is 21.7 °C. See live swimming conditions, weather and quality in the BrrChecker app.

How warm is the water at Lake Ontario?
Currently 21.7 °C (updated continuously).

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