Lake Ontario water temperature
Lake Ontario, Cape Vincent · Lake
The current water temperature at Lake Ontario is 23.9 °C (as of August 7, 2026, source: NOAA CO-OPS).
23.9 °C
Frequently asked questions
Can you swim at Lake Ontario right now?
The current water temperature is 23.9 °C. See live swimming conditions, weather and quality in the BrrChecker app.
How warm is the water at Lake Ontario?
Currently 23.9 °C (updated continuously).
How warm is at Lake Ontario in August?
In August, the water temperature recently averaged 23.2 °C.
