A heat warning has been issued for Niagara.
Hot and humid conditions will continue this week, with high humidex values expected.
Daytime temperatures will reach the high 20's to low 30's Wednesday and Thursday.
The high temperatures will combine with high humidity to result in humidex values near 40 each day.
High temperatures Friday may also reach the upper 20's with humidex values again approaching 40.
Warm temperatures above 20 degrees each night will provide little relief from the heat.
Cooler and less humid air is expected to arrive Friday or by this weekend.
Hot and humid air can also bring deteriorating air quality and can cause the Air Quality Health Index to approach the high risk category.
Extreme heat affects everyone, and the risks are greater for young children, pregnant women, older adults, people with chronic illnesses and people working or exercising outdoors.
Officials advise you to drink plenty of water even before you feel thirsty and stay in a cool place.