The rain came down hard Saturday afternoon and evening with most locations in northern Illinois receiving over one inch of rainfall. Most of Sunday afternoon has been quiet, however, there has been a steady increase in showers from south to north Sunday evening. Rain coverage will increase as a deep low pressure system moves out of the central Plains and into the upper Midwest later tonight.
Most of the rain will arrive by midnight before turning to a little drizzle or just light showers during the overnight. Thunderstorm coverage has increased south of Aurora and should mostly remain to the southeast of the immediate Stateline. Although I can't completely rule out a thunderstorm or two this evening. Severe weather is not expected. Although if thunderstorms do occur, rainfall totals may increase closer to an inch. Overall, an additional half to three quarters of an inch of rain is expected to fall between Sunday evening and Monday evening.
Temperatures will remain mild, and may actually rise a couple degrees as the wind shifts around to the southwest. Overnight lows will remain in the mid to upper 40's.
This image to the left is a simulated radar image (future radar) right around 10pm. Around this time there could be a few thunderstorms, but as drier air is pulled northward the rain should come to an end with only drizzle and fog through the night.