Environment Canada ended the extreme cold warning for Sarnia-Lambton late Monday morning.
It had been posted since Saturday morning when a sharp cold front ushered in frigid arctic air and strong north-northwest winds produced dangerous wind chills.
An extreme cold warning is issued when wind chills of -30 C or colder are forecast.
The temperature at Sarnia's Chris Hadfield Airport dropped as low as -28 C at 7am Monday. The wind chill was -32 C at 3am. Unofficially, low temperature records have been broken in numerous centres across southern Ontario.
The cold front brought strong northwest winds that created whiteout conditions Saturday into Sunday. There were numerous collisions and road closures in snow belt areas southeast of Lake Huron including along parts of Hwy. 402.
It will remain very cold Family Day Monday with a wind chill of -26 C.