http://www.theweathernetwork.com/news/storm_watch_stories3&stormfile=Heat_could_trigger_severe_storms_across_Ontario_28_05_2012

Temperatures over 30 degrees could feel like 40 with the humidex.

The rising heat could also lead to widespread thunderstorms across the province late Monday afternoon.

The storms will work their way down Lake Superior and then spread across northeastern Ontario. There's a risk in parts of southern Ontario through the overnight as well. 

Some of these storms have the potential to be severe in nature with wind gusts up to 90 km/h as well as large hail. According to Environment Canada, an isolated tornado in the Nickel Belt region isn't out of the question either. Residents are urged to stay up-to-date with the warnings in their area and to take the necessary precautions if severe weather moves through. 

Heavy rain is expected across much of northern Ontario, which is a relief to firefighters who've had their hands full withwidespread wildfires.