Environment Canada issued a storm watch for Caledon just before 2 p.m. and said conditions are favorable for the development of dangerous storms that could bring damaging wind gusts and heavy rain.
According to the warning, the storm could bring wind gusts of up to 90 kilometers per hour as well as heavy rainfall with local amounts of 20 to 40 millimeters this afternoon and early this afternoon.
Severe thunderstorm watches are also in effect for Barrie and Collingwood to the north and most areas west of Windsor.
There are currently no warnings for Toronto, although rain is expected in the evening.
The alerts come as warm conditions continue in the region. A high of 29 degrees Celsius is expected in Toronto on Monday. There is a 60 percent chance of showers in the evening and after midnight and a chance of a thunderstorm this afternoon.
The warm weather is expected to continue over the next few days, with highs of 26 expected on Tuesday and 30 on Wednesday.
