DES MOINES, Iowa — Observed rainfall totals for Tuesday, September 15, 2026 show widespread 1 inch or greater rainfall across central Iowa, with some areas recording over 3 inches in a single day. The rainfall was concentrated in a broad corridor stretching from Omaha and Lincoln eastward through Des Moines, Cedar Rapids and Davenport, with the heaviest totals clearly visible in the deep red and orange zones on the observed precipitation map. Meanwhile, Illinois and Indiana experienced a classic have and have not rainfall pattern, where some communities received meaningful rain while nearby areas missed out entirely.
Where the Heaviest Rain Fell Tuesday September 15
The observed rainfall map for Tuesday, September 15, 2026 through 12:00 AM Wednesday, September 16 shows a concentrated band of heavy rainfall cutting across central Iowa and into neighboring states. Here are the cities visible within and around the heaviest rainfall zones:
- Des Moines, Iowa sits directly within the deepest red zone on the observed rainfall map for Tuesday, September 15, 2026, confirming it as one of the hardest-hit cities with rainfall totals well above 1 inch and locally over 3 inches possible in the metro area.
- Omaha, Nebraska and Lincoln, Nebraska fall within the western end of the heavy rainfall corridor on the Tuesday, September 15 observed map, receiving widespread 1 inch plus totals as the rain band extended westward into eastern Nebraska.
- Cedar Rapids, Iowa and Davenport, Iowa are visible within the heavy rainfall zone on the observed map, sitting in the eastern extension of the widespread 1 inch plus corridor across central Iowa.
- Waterloo, Iowa and Ames, Iowa fall within the widespread 1 inch plus rainfall zone outlined by the yellow dashed oval on the Tuesday, September 15 observed precipitation map.
- Dubuque, Iowa is visible on the eastern edge of the widespread rainfall zone on the Tuesday, September 15 observed map.
- Burlington, Iowa is visible on the southeastern portion of the widespread rainfall zone on the Tuesday, September 15 observed precipitation map.
- Sioux City, Iowa and Sioux Falls, South Dakota are visible on the western edge of the broader rainfall footprint for Tuesday, September 15, 2026.
- Saint Joseph, Missouri and Topeka, Kansas are visible on the southwestern portion of the rainfall map within the broader precipitation footprint for Tuesday, September 15.
- Yankton, South Dakota and Norfolk, Nebraska are visible on the northwestern edge of the rainfall map within the broader storm environment for Tuesday, September 15, 2026.
The Have and Have Not Pattern Across Illinois and Indiana
While central Iowa saw widespread and impressive rainfall totals on Tuesday, September 15, 2026, the source data specifically identifies Illinois and Indiana as experiencing a scattered have and have not pattern. The map labels this zone directly near Urbana, Illinois and the surrounding area with an arrow pointing to the have and have not designation. This means:
- Some communities in Illinois and Indiana received meaningful rainfall on Tuesday, September 15, while communities just a few miles away saw little to nothing from the same storm system.
- Cities visible within the scattered Illinois and Indiana rainfall zone include Peoria, Bloomington, Springfield and Quincy, Illinois as well as Indianapolis, Kokomo, Muncie and Fort Wayne, Indiana, all of which fall within the broader but uneven rainfall footprint on the Tuesday, September 15 observed map.
- Chicago, Illinois and Gary, Indiana are visible on the northern portion of the map within the broader storm environment, with scattered totals across the metro area reflecting the uneven pattern seen across both states.
- Urbana, Illinois is specifically identified on the map with the have and have not label, confirming this city as a prime example of the scattered rainfall distribution seen across Illinois and Indiana on Tuesday, September 15, 2026.
- Kankakee, Illinois and Waukegan, Illinois are visible on the map within the broader Illinois rainfall environment for Tuesday, September 15.
Michigan Also Sees Heavy Rainfall Tuesday
The observed map for Tuesday, September 15, 2026 also shows a separate band of heavy rainfall across portions of Michigan, distinct from the central Iowa corridor. Cities visible within the Michigan heavy rainfall zone include:
- Traverse City, Petoskey and Cadillac, Michigan are visible within a concentrated orange and red rainfall band on the northeastern portion of the Tuesday, September 15 observed map.
- Marinette, Wisconsin and Green Bay, Wisconsin fall within the heavy rainfall band extending across the Great Lakes region on the Tuesday, September 15 observed precipitation map.
- Escanaba, Michigan and Rhinelander, Wisconsin are visible in the northern portion of the rainfall footprint on the Tuesday, September 15 observed map.
- Muskegon and Grand Rapids, Michigan are visible within the broader Michigan rainfall zone on the Tuesday, September 15 observed precipitation map.
Wisconsin Cities Also Receive Tuesday Rainfall
Several Wisconsin cities are visible within meaningful rainfall zones on the Tuesday, September 15, 2026 observed precipitation map:
- Madison, Wisconsin and Milwaukee, Wisconsin fall within the rainfall footprint visible on the Tuesday, September 15 observed map, with totals varying across the metro areas based on the scattered nature of the storm system.
- Wausau, Oshkosh, Fond du Lac and West Bend, Wisconsin are visible within the rainfall zone on the Tuesday, September 15 observed map.
- Racine and Waukegan fall within the southern Wisconsin and northern Illinois rainfall zone on the Tuesday, September 15 observed precipitation map.
