Lake Ontario water temperature

Lake Ontario, Sodus Point, NY · Lake

The current water temperature at Lake Ontario is 21.3 °C (as of August 30, 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.

21.3 °C

Measured: August 30, 2026 · continuously updated

💧 Water 21.3° · ☀️ Air 21.3° · high today 24.6°

Temperature trend of recent weeks

Lake Ontario — Photo: DanielPenfield · CC BY-SA 4.0 · Wikimedia Commons

Measurement series & statistics

This measurement series includes 1248 data points since July 3, 2026.

Lowest recorded value: 16.1 °C on July 12, 2026 · highest value: 24.4 °C on August 14, 2026.

Nearby waters

Lake Ontario, Sodus Point Nearshore Monitoring · 1.5 km away23.0 °C Lake Ontario, Oswego, NY (274) · 39.3 km away22.4 °C Lake Ontario, Oswego · 42.5 km away22.2 °C Irondequoit Creek above Blossom Rd near Rochester, New York · 47.6 km away19.6 °C Allen Creek near Rochester, New York · 49.3 km away20.2 °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 Prince Edward Pt21.7 °C

Frequently asked questions

Can you swim at Lake Ontario right now?
The current water temperature is 21.3 °C. See live swimming conditions, weather and quality in the BrrChecker app.

How warm is the water at Lake Ontario?
Currently 21.3 °C (updated continuously).

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