Lake Ontario Water Temperature

(Today) Nov 2025

11.7°C / 53°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

7°C / 45°F
(overcast clouds)
Partly cloudy
Wind
36 mph
Humidity
94%

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.