Environment Canada is warning boaters and residents in Whitby, Ontario, to be ready for possible thunderstorms on Thursday, August 6, 2026. The marine forecast for Western Lake Ontario, issued on August 5 at 10:30 a.m., calls for scattered showers and a risk of storms developing in the afternoon and evening.
According to the Environment Canada forecast, the unsettled weather will begin overnight with showers and a risk of thunderstorms, continuing into Thursday. Mariners on Lake Ontario near Port Whitby should keep an eye on the sky and be prepared to head for shelter if storms move in. Winds will be light through the morning before turning west at 10 knots in the afternoon, then becoming light again by evening, with waves expected to stay under half a metre.
The Port Whitby Marina, a 420-slip facility run by the Town of Whitby, is in peak season right now. With docks full of boats and many people out on the water, the marina office is a key contact for local boaters who need updates. Anyone planning to be on the lake Thursday should check the latest forecast before heading out, and monitor marine radio for any warnings.
The extended forecast shows light winds Friday, southwest winds up to 15 knots Saturday, and west winds at 15 knots Sunday. August is typically the busiest month for thunderstorms in southern Ontario, and this forecast reminds boaters that conditions can change quickly on the lake.
Environment Canada issues marine forecasts for the area several times a day from its storm prediction centre in Toronto. A “risk of thunderstorms” indicates conditions are favorable for storm development. Boaters should have a plan for where to go if the weather turns, and always put safety first when thunder roars.