Environment Canada has ended a heat warning for the Sarnia region.
A hot and humid airmass kept daytime maximum highs of 31 C or higher were expected on both Sunday and Monday with Humidex values near 40 C.
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.
A cold front began moving through the area Monday night.