Wednesday will be another scorching day in parts of central and eastern Canada.
has issued several heat warnings for southern Ontario and southern Quebec with highs expected near 31 C and a humidex exceeding 40 C.
The warnings stretch from Windsor to Hamilton in Ontario and from Gatineau to the Eastern Townships in Quebec.
Environment Canada says a very hot and humid southeasterly airmass is slowly moving through the region.
It says strong thunderstorms are possible.
The weather agency says a cold front will return temperatures back to seasonal levels beginning in Ontario late Wednesday night and in Quebec by Thursday morning.