Lake Ontario Water Temperature
(Today) Jun 2025
13.1°C / 55.5°F
The water will feel cool (fresh). Probably too cold for all but seasoned swimmers. We'd recommend a 4mm or 5mm wetsuit if you want to stay in the water.
Current weather
16°C / 60°F
(broken clouds)
(broken clouds)
Wind
14 mph
Humidity
84%
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.
Based on readings from St. Catharines