The Saugeen Conservation Authority is issuing a Flood Advisory Bulletin.
The Authority says with the possibility of 25 to 35 millimetres of rain overnight, river levels can be expected to reach spring flood values.
Flooding of traditional low lying areas is expected.
However, the return to freezing temperatures Wednesday will help to naturally control further runoff and reduce peak flows.
An update will be released Wednesday, depending on the amount of rain received overnight.
The Authority is reminding people to stay away from streams, rivers, and any remaining ice cover.