Saturday: Cloudy skies. Heavy rain at times (south), scattered showers/thunderstorms (north). Flood Watch for southern portions of Chicagoland for the duration of the day. ENE 5-10 mph. High 79, mid 70s by the lake. 

NWS Chicago says the highest flood threat area is along and south of the Kankakee River Valley.

Saturday Night: Scattered showers/thunderstorms. ESE 10-20 mph. Low 70

Sunday: Peeks of AM sun. scattered PM showers/thunderstorms become more numerous and widespread later in the day–some could be strong to severe. ENE 10-20 mph. High 84, cooler

Damaging winds, hail and locally heavy rainfall are possible with severe weather coming Sunday evening.

Chicago Area Radar | WGN TV

Extended outlook calls for a chance of showers/t’storms on Monday with highs in the mid 80s. Drier weather on Tuesday with partly sunny skies and still a bit muggy. Highs in the mid 80s. Wednesday sees some filtered sunshine with building clouds. Highs in the mid 80s. Showers/thunderstorms return to the forecast Thu/Friday with highs in the muggy low 80s.