Environment Canada issued a snowfall warning for Sarnia-Lambton Friday afternoon with a low pressure system approaching.
Warnings are also in effect for London-Middlesex, Chatham-Kent, Windsor-Essex, Oxford-Brant and Toronto.
The weather agency said Sarnia-Lambton is expected to get five centimetres of snow overnight and another five to 10 centimetres Saturday.
Gusty southerly winds will also cause local blowing snow and reduced visibility in areas particularly Saturday morning.