Chicago, Illinois – Streets across northern Illinois are at risk of flooding within minutes early this morning as intense thunderstorms push rainfall rates up to 2 inches per hour into ground that cannot absorb any more water.
According to the National Weather Service in Chicago, a Flood Watch remains in effect until 5 a.m. Saturday, with the heaviest rain moving through right now into the pre-dawn hours. Forecasters say soils are already saturated, especially near the Illinois-Wisconsin border, meaning runoff is immediate. That is turning intersections, underpasses, and low-lying roads into fast-forming flood zones during the most dangerous time of day for visibility.
For early-morning drivers already on the road, conditions can change block by block. Water may pool quickly along major corridors including I-90, I-88, and surface streets across Chicago, Cicero, and Oak Park. Underpasses are a major concern this morning, where stalled vehicles and sudden deep water can trap drivers with little warning. Emergency crews often respond to rescues in these exact conditions before sunrise.
Suburbs from Schaumburg to Joliet and west toward DeKalb are also seeing rapid runoff. Neighborhood streets, parking lots, and poorly drained intersections could flood even from short bursts of heavy rain. Creeks and retention ponds are already elevated, leaving little room for additional water.
This morning’s storms are setting up a longer-lasting problem. In Rockford, the Rock River was at 4.2 feet late Friday and is now expected to rise toward or above its 6.0-foot flood stage by Monday. At 5.0 feet, water reaches low-lying areas of Blackhawk Island and Field Gem Park. By 5.5 feet, sections of the Rock River Recreation Trail begin to flood, and higher levels could threaten neighborhoods in Loves Park.
Elsewhere, the Illinois River near Ottawa is expected to approach flood stage by early Sunday morning, with backwater impacts pushing into nearby communities and critical areas near St. Elizabeth Medical Center. In northwest Indiana, the Kankakee River is also rising, with flood stage possible by early Monday in areas near Dunns Bridge and Shelby.
What falls this morning will continue moving through rivers for days, extending the flood risk well beyond sunrise.
If you are driving now, avoid any water-covered roads. Just 6 to 12 inches of moving water can carry away a vehicle. Keep headlights on in heavy rain, allow extra travel time, and be ready to reroute quickly. Residents near rivers should prepare for rising water through the weekend.
The most dangerous window is unfolding right now through the early morning hours. Additional updates are expected later this morning, with more flood warnings likely as rivers respond to the overnight rain.
