Lake Ontario water temperature

Lake Ontario, Centre Island Beach · Lake

The current water temperature at Lake Ontario is 20.0 °C (as of September 6, 2026, source: City of Toronto).

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

20.0 °C

Measured: September 6, 2026 · continuously updated

💧 Water 20.0° · ☀️ Air 18.3° · high today 22.6°

Nearby waters

Lake Ontario, Gibraltar Point Beach · 0.9 km away20.0 °C Lake Ontario, Hanlan's Point Beach · 1.9 km away20.0 °C Lake Ontario, Ward's Island Beach · 2.3 km away20.0 °C Lake Ontario, Cherry Beach · 3.4 km away21.0 °C Lake Ontario, Sunnyside Beach · 6.6 km away15.0 °C

More measuring points: Lake Ontario

Sodus Point Nearshore Monitoring23.0 °C Niagara-on-the-Lake (ECCC)22.6 °C Oswego, NY (274)22.4 °C Oswego22.3 °C Sodus Point, NY22.2 °C Wolfe Island (ECCC)22.2 °C

Frequently asked questions

Can you swim at Lake Ontario right now?
The current water temperature is 20.0 °C. See live swimming conditions, weather and quality in the BrrChecker app.

How warm is the water at Lake Ontario?
Currently 20.0 °C (updated continuously).

← All waters · Warmest lakes to swim today · Water temperature in Canada