Unusual swings in temperature have created the potential for heavy fog across parts of the region.
Environment Canada has issued a fog advisory for Windsor-Essex, Chatham-Kent, Sarnia-Lambton, and London-Middlesex that will be in effect from Tuesday evening until late Wednesday morning.
The weather agency said there was the possibility of zero visibility in some areas, which can make travel very difficult.
"Fog is occurring, causing significantly reduced visibilities," read the alert from Environment Canada. "The fog will remain in place tonight and is expected to lift late Wednesday morning or early afternoon. Visibility may be significantly and suddenly reduced to near zero. Travel is expected to be hazardous due to reduced visibility in some locations."
The fog advisory comes as much of southwestern Ontario has experienced milder-than-usual temperatures coming out of the New Year's weekend.
