Environment Canada says it has declared a heat warning for Toronto on Sunday and Monday as temperatures soar into the 30s.

The City of Toronto has opened up six emergency cooling centres as temperatures soar into the 30s.

Toronto Public Health says people can find respite from the heat in seven cooling stations across the city with temperatures expected to reach the mid-30s.

As families prepare for the return of school this week and settle into new daily routines leading into the fall, hot and humid weather is set to return.

The next couple of days will be a scorcher in Toronto as daytime temperatures are expected to reach the mid to upper 30 degrees Celsius with the humidex.

A heat warning has been issued for Toronto and all of southern Ontario with temperatures expected to feel as hot as 40 C with the humidity, comparable to some of the hottest places on earth.