Toronto is under a heat warning as hot and humid conditions are expected Monday through Tuesday, according to Environment Canada.

Maximum daytime temperatures between 31 and 34 degrees Celsius are expected over the next couple of days with humidex values near 40.

However, overnight low temperatures are forecast to fall between 21 and 23 degrees Celsius.

Environment Canada says a cold front on Tuesday evening is expected to bring showers and thunderstorms providing an end to the heat and humidity.

Hot and humid air can also cause worsening air quality resulting in the Air Quality Health Index to approach the high risk category, Environment Canada says.