Environment Canada issued a humidex advisory Monday for Toronto and parts of southern Ontario.

As hot and humid air moves into southern Ontario from the American Midwest on Tuesday, temperatures are expected to hover in the low to mid-30s with humidex values in the 40s.

They warn that the high humidex readings may make it feel like the hottest day of the summer.

On Wednesday, humidex values will likely remain near 40. They said that temperatures are expected to return to near seasonal values by Thursday.

MORE ON THESTAR.COM

Seasonal weather conditions expected for fall

More rain than usual expected this fall