Residents in Oshawa can expect a shift to unsettled weather on Tuesday, as Environment Canada forecasts a risk of thunderstorms for the afternoon of June 9, 2026. The heat and humidity will also make it feel much warmer than the actual temperature, with a humidex of 35 expected.
The day will start mainly sunny, but clouds are expected to increase late in the morning. By the afternoon, there is a 40 percent chance of showers, along with the risk of a thunderstorm. Winds are expected to become southwest at 20 km/h in the afternoon. The high temperature is forecast to reach 29°C, but with the humidity, it will feel like a sticky 35°C.
This comes after a sunny Monday with a high of 26°C. As of Monday afternoon, no weather alerts were in effect for Oshawa or the Durham Region, meaning the thunderstorm risk remains a forecast and not yet an imminent threat. The warm and humid pattern is expected to stick around through Thursday, with highs near 30°C and a chance of showers continuing.
While the forecast does not meet official heat warning criteria for southern Ontario, which requires either a humidex of 40 or higher for at least two consecutive days, or daytime highs of 31°C or above with overnight lows of 20°C or above for two days, the conditions will still be uncomfortable for many. Oshawa’s normal high for early June is 23°C, putting the forecast well above average.
For those needing relief from the heat, the Region of Durham has cooling centres available, including the South Oshawa Community Centre at 1455 Cedar Street. Residents are encouraged to check on vulnerable neighbours and stay hydrated.
