A heat warning issued Wednesday for much of southern Ontario, including Sarnia-Lambton, Chatham-Kent, Windsor-Essex and London-Middlesex, finally ended Sunday.
Environment Canada ended the warning at around 10am saying conditions were no longer expected to reach severe criteria.
The mid-summer heat wave saw temperatures hit the mid 30 C range at times with the humidex around 40 C.
The national weather agency says muggy conditions are expected to prevail into Monday with the humidex near 36 C (97 F).
The Sarnia fire department's city-wide fire ban due to air quality concerns was expected to remain in effect until Monday.
A more comfortable low of 18 C (64 F) is forecast for Monday night and a mix of sun and cloud and a high of 28 C (82 F) Tuesday.