Multiple rounds of showers and thunderstorms are expected through Wednesday evening, adding to the high rain levels that have fallen since Monday.

The National Weather Service has issued a flood watch until 1 a.m. Thursday for most of northern Illinois.

Creeks and streams that are already elevated may rise over their banks.

Local flooding may occur in poor drainage areas, and roads could fill with water, causing hazardous driving conditions.

The 2.43 inches that fell Tuesday at O’Hare International Airport in Chicago makes it the sixth rainiest April day on record there, the NWS said.

It was the rainiest April day since April 18, 2013, when 3.54 inches fell.