Historic April Flooding Across Northeast Wisconsin

A series of heavy precipitation events resulted in record setting and historic flooding on several rivers across northeast WI from mid to late April 2026. The total precipitation for the month of April in Green Bay was 8.56 inches, which exceeded the previous record for the month by over 2 inches (6.47 inches set in 1929). Similarly, April's monthly precipitation at Wausau of 8.74 inches broke the previous record by over 2.5 inches (6.06 inches set in 1954). After two moisture laden ice storms impacted the region at the start of the month, a volatile period of thunderstorms with heavy rain occurred from Sunday, April 12 through Tuesday, April 14. Flash flooding occurred late Monday night (April 13) through Tuesday evening (April 14). Areas hardest hit included the Suamico and Green Bay areas, where water rescues occurred near the Suamico River on the morning of April 14, and in the Green Bay metro during the evening of April 14. Due to the extreme heavy rain of 4-6 inches noted over portions of Waupaca and Shawano counties, multiple dams experienced overtopping, with some at risk of failing. Several Flash Flood Watches and Warnings were issued for the potential dam failures Tuesday, April 14 into Wednesday, April 15.       

The heavy rainfall especially impacted the Wolf River basin, leading to record setting flooding for the Wolf River at Shiocton and the Wolf River at New London. Record flooding also occurred on other rivers over northeast WI, including the Embarrass River near Embarrass and the Peshtigo River near Porterfield. A record high level was also set on the Wolf River near Lake Poygan. In total, 47 river flood warnings were issued from late March through early May. Some river flood warnings were in effect for nearly one month!  

The river flooding resulted in tremendous disruptions to daily life for those living along and near the Wolf River and Embarrass River. Evacuations occurred in the towns of Shiocton and New London for multiple days. Power and gas was shutoff in these areas as flood waters impacted many homes and businesses. The peak of the flooding along the Wolf River occurred from April 16 through April 21.  

Flooding then moved downstream on the Wolf River, impacting the Fremont and Winneconne areas, as well as areas along Lake Poygan. Eventually the higher flows on the Wolf River and the lower Fox River resulted in the rising levels on Lake Winnebago, with prolonged minor flooding noted on the western and northern side of Lake Winnebago in Oshkosh, Neenah, and Menasha.

April 2026 Total Precipitation

April 2026 Precipitation Departures from Normal