September Rainfall Varied Across Mississippi Valley (WI)

La Crosse, WI – September finished warmer than normal across the Upper Mississippi River Valley, while rainfall varied considerably from one part of the region to another.

According to the National Weather Service in La Crosse, September 2026 featured above-normal temperatures across its forecast area, which includes portions of Wisconsin, Minnesota and Iowa. The agency described precipitation during the month as “highly variable.”

NWS climate maps show temperatures running above 1991-2020 normals across most of the region. La Crosse and Rochester, Minnesota, both finished the month warmer and wetter than normal.

At La Crosse, September ranked as the 20th-warmest September on record and tied for the 15th-wettest, according to the NWS monthly climate summary.

Rochester recorded its 14th-warmest September and 16th-wettest September on record.

The broader rainfall pattern was much less uniform. NWS precipitation maps show drier-than-normal conditions across portions of northern Wisconsin and Minnesota, while wetter conditions were concentrated farther south, including parts of southern Wisconsin, southeastern Minnesota and northeastern Iowa.

Severe weather activity was also above normal during September. The NWS summary documented severe thunderstorm, tornado and flash flood warnings across portions of its service area during the month, with warning activity varying significantly by county.

The climate report is a review of observed September conditions rather than an October forecast. It shows that warmth was widespread across the Upper Mississippi River Valley even as rainfall totals differed sharply over relatively short distances.

Residents should look to separate NWS forecasts and outlooks for conditions expected during October.