Daily Forecast: June 18, 2025

Another hot and humid day is expected across the region tomorrow, along with showers and thunderstorms for many areas. Eastern and Central Ontario will see mainly sunny skies for much of the day.

There will be a risk for severe weather tomorrow for much of the day. There will likely be two rounds of thunderstorms, with one in the late morning to early afternoon, and one in the evening. Any thunderstorm through the day will bring the risk of heavy rainfall and flash flooding, with the potential for rainfall of 60 millimetres within one hour. The strongest storms are expected in the evening, bringing the potential for wind gusts up to 100 km/h, the risk for a tornado, and hail 3 to 4 centimetres in diameter.

Remember to stay hydrated tomorrow and take frequent breaks if working outdoors. We continue to monitor a heat wave beginning on the weekend and through much of next week. Temperatures over 30ºC will be possible, with humidex values in the mid 40s. Further information is available in our Primary Message.