Lake Ontario Water Temperature
(Today) Sep 2024
20.6°C / 69°F
The water will feel tepid. Swimming will be tolerable without a wetsuit, although it will take a little getting used to. If you intend to stay in the water for a while a 3/2mm wetsuit will be ideal.
Current weather
11°C / 51°F
(broken clouds)
(broken clouds)
![Partly cloudy](/images/weather/partly_cloudy.png)
Wind
20 mph
Humidity
79%
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Water temps is based on average surface temperatures measured throughout Lake Ontario.
Map showing Lake Ontario locations. Click on pins to view water temperature.
16 locations listed in Lake Ontario.