Lake Ontario water temperature

Lake Ontario, Oswego, NY (274) · Lake

The current water temperature at Lake Ontario is 22.4 °C (as of August 31, 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.

22.4 °C

Measured: August 31, 2026 · continuously updated

💧 Water 22.4° · ☀️ Air 21.1° · high today 24.1°

Temperature trend of recent weeks

Lake Ontario — Photo: Dougtone · CC BY-SA 2.0 · Wikimedia Commons

Measurement series & statistics

This measurement series includes 1425 data points since July 3, 2026.

Lowest recorded value: 17.5 °C on July 12, 2026 · highest value: 24.9 °C on August 6, 2026.

Nearby waters

Lake Ontario, Oswego · 3.9 km away22.2 °C Lake Ontario, Sodus Point, NY · 39.3 km away21.3 °C Lake Ontario, Sodus Point Nearshore Monitoring · 39.3 km away23.0 °C Lake Ontario, Prince Edward Pt · 44.6 km away21.7 °C Atlantic, 20NM North Northeast of Rochester, NY · 71.8 km away21.2 °C

More measuring points: Lake Ontario

Sodus Point Nearshore Monitoring23.0 °C Cape Vincent22.3 °C Oswego22.2 °C Grimsby21.7 °C Prince Edward Pt21.7 °C Sodus Point, NY21.3 °C

Frequently asked questions

Can you swim at Lake Ontario right now?
The current water temperature is 22.4 °C. See live swimming conditions, weather and quality in the BrrChecker app.

How warm is the water at Lake Ontario?
Currently 22.4 °C (updated continuously).

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