The heat warning continues for Niagara today.
A minor cold front has ushered in a slightly cooler and less humid air mass but temperatures today are still expected to be above 30 degrees with humidex values around 43.
The extreme heat event is expected to stick around till Thursday.
Overnight low temperatures are expected to be in the low twenties, except high teens in some rural areas, providing little or no relief from the heat.
A slight cool down is expected Friday.