Niagara is under a heat warning.
Daytime high temperatures are expected to reach 30 to 33 degrees beginning this afternoon.
Humidex values will likely be near 40.
Overnight low temperatures are expected to be 20 to 22 degrees, providing little relief from the heat.
Hot and humid conditions will continue into tomorrow (Thursday), but showers and thunderstorms should cool things off in the evening.
Heat-related risks are greater for young children, pregnant women, older adults, people with chronic illnesses and people working or exercising outdoors.
Officials say you should drink plenty of water even before you feel thirsty and stay in a cool place.
Never leave people or pets inside a parked vehicle.