It’s going to be a wet start to the week.

A low-pressure system carrying rain is moving into southern Ontario from the southwest, and is expected to hang around through Tuesday until early Wednesday.

Rain moved into areas near Windsor and Chatham-Kent around noon Monday, and began to menace the London region by late afternoon.

Waterloo Region is expected to receive its first soaking Monday evening.

Environment Canada says most areas will see between 20 and 40 mm of precipitation off and on as the system moves through, although those numbers could be higher in some areas.

While there is a chance of thunderstorms for as long as the system remains above Ontario, forecasts suggest most of the rain will fall without being accompanied by thunder and lightning.