THE WEATHER BEAT · SEP 20

The rain is over in eastern Iowa. The Mississippi crest arrives Wednesday

Heavy rain ended Saturday night in eastern Iowa. The water it left is now scheduled: six Mississippi River towns are forecast to flood from Wednesday.

By the Weather Rock September 20, 2026, 2:49 p.m. · 9 min read

Hannibal, Missouri, on the Mississippi River — Hannibal, Missouri, and the Mississippi River seen from Lover's Leap south of town, photographed on 31 May 2005. Photo: Kelly Martin, Wikimedia Commons, CC BY-SA 3.0. This crop carries the same licence.

Key points

The heavy rain that fell on eastern Iowa from Thursday into Saturday night is finished, and the National Weather Service office at the Quad Cities said so in its 1:22 p.m. CDT discussion today: "The widespread heavy rains are over."
The water is not finished. Six Mississippi River gauges from Canton, Missouri down to Winfield, Missouri were put under flood warnings at 11:48 a.m. CDT today for flooding that does not begin until Wednesday.
Two Iowa rivers were upgraded today from moderate to major flooding: the English River at Kalona and the Wapsipinicon near De Witt.

Lock and Dam No. 24 on the Mississippi River at Clarksville, Missouri, photographed on 2 June 2018. Photo: Paul Sableman, Wikimedia Commons, CC BY 2.0.

What happened, and where the water went

The rain stopped. That is the honest headline in eastern Iowa this afternoon, and the forecasters there wrote it plainly. The Quad Cities office, in the discussion it issued at 1:22 p.m. CDT, led with the line that the widespread heavy rains are over, that a small upper low will keep spinning nearby with showers and cool cloudy conditions through Tuesday morning, and that additional rain over the next 24 hours will be very light. It also reported that on the creeks under areal flood warnings this morning, including Indian Creek in Linn County, "the water was reported to have stopped rising early this morning."

So the sky is done with it. The ground is not, and neither is the river system, because a river is a delivery schedule. What fell on Iowa Thursday through Saturday has to get to the Gulf, and the gauges along the way tell you when it will pass each town.

Close to the rain, the crest is already here or nearly here. The English River at Kalona stood at 17.6 feet at 9 a.m. CDT and was still slowly rising toward a crest of 18.1 feet this evening, against a flood stage of 14 feet. That gauge got the day's most serious wording: the Quad Cities office changed its forecast for Kalona from moderate to major severity, and the product says at 18 feet water has overtopped 130th Street, Kiwi Avenue, Orange Avenue and Poplar Avenue, and begins backing into town on the north side of the river. The Wapsipinicon near De Witt got the same upgrade with a slower clock, moderate flooding happening now and major flooding forecast at a crest of 13 feet Wednesday afternoon into Thursday, where water affects many residences along the river.

Then the handoff. The Rock River at Moline, Illinois was 9.5 feet and rising this morning and is not expected to reach its 12 foot flood stage until Monday evening, cresting at 13.6 feet Tuesday evening. Farther down, the Iowa River at Marengo goes over this evening. Each of those is water that fell days ago, moving.

The last stop in today's paperwork is the main stem. At 11:48 a.m. CDT the St Louis office issued flood warnings for six Mississippi River gauges at once: Canton, LaGrange, Saverton, Hannibal, Clarksville and Winfield, all in Missouri, with the Illinois bank counties named alongside. Not one of them is above flood stage today. Canton was at 7 feet this morning against a 15 foot flood stage. Saverton was at 7.7 feet against 16. The warnings begin Wednesday and run into next weekend, and every crest in the set lands Thursday or Friday.

What makes those products worth reading is that the Weather Service says exactly what goes under at each number, and the numbers are small and specific. At Canton, 16.6 feet puts water on Front Street leading to the campground. At LaGrange, 18 feet floods the entrance to the lower parking lot at the Mark Twain Casino and sends cars around to another entrance. At Hannibal, 18 feet floods the north end of Southside Recreation Park Number 2 along Bear Creek, the gate wells are shut down to keep the sewers from backing up, and the pumps go to standby. At Saverton, 15.5 feet floods the access road to the raised riverside homes on the river side of the Sny levee. At Clarksville, 29 feet puts water into the parking lot entrance at the Riverfront Park. At Winfield, 27.5 feet is the stage at which Lock and Dam 25 stockpiles 200 tons of sand, 12,000 sandbags and 10,000 square feet of polyethylene plastic as a precaution.

That last one is the whole story in one sentence. Somebody in Winfield now has four days to move sand, because a river in Iowa stopped rising this morning.

Mississippi River, the six gauges under warning

Gauge	Flood stage	Stage Sunday morning	Forecast crest	Crest expected
Canton, MO	15.0 ft	7.0 ft at 10:00 a.m. CDT	16.6 ft	Thursday evening
LaGrange, MO	17.0 ft	8.6 ft at 11:00 a.m. CDT	17.9 ft	early Thursday afternoon
Saverton, MO	16.0 ft	7.7 ft at 10:00 a.m. CDT	18.2 ft	early Friday morning
Hannibal, MO	17.0 ft	11.6 ft at 11:15 a.m. CDT	18.2 ft	early Friday morning
Clarksville, MO	25.0 ft	17.8 ft at 11:30 a.m. CDT	28.2 ft	Friday morning
Winfield, MO	26.0 ft	18.0 ft at 11:30 a.m. CDT	27.4 ft	Friday evening

All six are forecast for minor flooding. From the flood warnings issued by NWS St Louis at 11:48 a.m. CDT on 2026-09-20, which state that river forecasts are based on observed precipitation plus forecast precipitation for the next 24 hours.

Upstream, where the water is now

Gauge	Flood stage	Stage Sunday morning	Forecast crest	Severity in the product
English River at Kalona, IA	14.0 ft	17.6 ft at 9:00 a.m. CDT, slowly rising	18.1 ft this evening	moderate occurring, major forecast
Wapsipinicon River near De Witt, IA	11.0 ft	11.7 ft at 9:30 a.m. CDT, slowly rising	13.0 ft Wednesday afternoon into Thursday	moderate occurring, major forecast
Rock River at Moline, IL	12.0 ft	9.5 ft at 8:30 a.m. CDT, rising	13.6 ft Tuesday evening	moderate forecast
Iowa River at Marengo, IA	15.0 ft	12.7 ft at 9:00 a.m. CDT, rising	15.4 ft overnight	minor forecast

From flood warnings issued by NWS Quad Cities IA IL between 9:23 a.m. and 10:10 a.m. CDT on 2026-09-20. Each of those products carries the same confidence note: rainfall from today through Monday night is expected to be considerably lighter than what fell Thursday through Saturday night, which is why the forecasters trust these river numbers.

Today, officially

As of the wire at 6:46 p.m. UTC there were 371 active National Weather Service alerts nationally, of which 43 were flood warnings across 10 offices and 20 were flood watches across 9. The Storm Prediction Center's day one outlook carried a highest risk category of slight, for thunderstorms with severe wind gusts and large hail across parts of Oklahoma and from eastern Colorado into far western Kansas, with isolated severe gusts and hail also possible from the southern Plains through the Ozarks and into the Ohio Valley. The National Hurricane Center's 15:00 UTC advisories carried Tropical Storm Fay in the Atlantic at 50 knots and Tropical Storm Odalys in the eastern Pacific at 40 knots, neither with a United States watch or warning.

Two of the wire's usual sources refused us today. The Storm Prediction Center's preliminary storm reports for yesterday and the Weather Prediction Center's day one excessive rainfall outlook both returned HTTP 403 to our fetcher, so this brief carries no yesterday report counts and no rainfall risk categories. That is our tool being turned away, not a quiet country, and it is said here rather than left as a silence.

One more note for anyone in the St Louis forecast area reading this: that office's own 12:35 p.m. CDT discussion says a cold front is moving through today with thunderstorms along it tonight, the best chance of rain all week, and that the severe potential is not being messaged for the event because the threat is limited. Any rain that falls tonight on the Missouri and Illinois side gets added to the numbers in the table above when the next river forecast runs.

This is a summary of official warnings, not emergency information. For live warnings see weather.gov and your local officials.

The rock's live forecast for the places in this story