A Special Weather Statement has been issued by Environment Canada for Windsor-Essex and Chatham-Kent.
It's because a messy mix of winter weather is on the way.
A system will start late Wednesday with 10-25mm of rain before changing to freezing rain and 4-8cm of snow by Thursday night.
The national weather agency says the track of the low pressure system is uncertain, and as such precipitation type, timing and amounts may change.
It warns of slippery roads, poor visibility and blowing snow.