Multi-day heat event continues. What: Daytime highs of 32 to 35 degrees Celsius, with humidex values of 37 to 42. Overnight lows of 20 to 23 degrees Celsius. When: Continuing through Tuesday or possibly Wednesday for some areas. Additional information: A cooler air mass is expected to arrive Tuesday night, bringing an end to this heat event. There is the possibility that eastern Ontario and the Greater Toronto and Hamilton Area could see hot and humid conditions continue into Wednesday. Hot and humid air can also bring deteriorating air quality and can result in the Air Quality Health Index approaching the high risk category. ### Heat warnings are issued when very high temperature or humidity conditions are expected to pose an elevated risk of heat illnesses, such as heat stroke or heat exhaustion. For more information: https://www.canada.ca/en/health-canada/services/climate-change-health/extreme-heat/how-protect-yourself.html https://www.canada.ca/en/health-canada/services/climate-change-health/extreme-heat/who-is-at-risk.html Please continue to monitor alerts and forecasts issued by Environment Canada. To report severe weather, send an email to ONstorm@ec.gc.ca or post reports on X using #ONStorm.