We’ll remember this steamy summer.

Yet another heat wave is on the way.

A hot and humid airmass from the U.S. is due to move into southern Ontario beginning Tuesday afternoon – and conditions will become considerably more humid Tuesday night.

Extreme heat and humidity is expected Wednesday through Friday – with afternoon temperatures reaching the low to mid 30s.

Warm and muggy nights won’t provide much of a break from the heat – but there may be some relief from the daytime sizzle – in a few areas near the shorelines of the Great Lakes – if a breeze off the lake develops.

Humidex values peaking in the upper thirties to low 40s are expected beginning Wednesday.

Environment Canada says the coming heat wave may be the longest and most significant one – so far this summer.