A heat warning in effect since Friday afternoon has finally ended for Sarnia-Lambton.
Environment Canada says hot and humid conditions will come to an end Wednesday.
Daytime temperatures will be near 30 C (86 F) Wednesday with humidex values in the upper 30s C.
Although temperatures may start off warm Wednesday, a cold front will move across southern Ontario through the day ushering in considerably cooler air by the end of the day.
The autumn heat wave saw several daytime high records broken across the region, including in Sarnia-Lambton.
The extreme heat also forced the cancellation of outdoor co-curricular activities Tuesday for area students.