Pool season · State index
Wisconsin Pool Season 2026: Opening & Closing Dates by City
Last updated: July 25, 2026 · 11 cities covered
Both halves of the pool year for all 11 covered Wisconsin cities. The median calendar runs May 13 to September 29. Every row links to a one-page season overview with the live water-temperature model; the opening and closing hubs carry the full checklists.
Wisconsin: a short-season pool state| City | Open by | Close by | 80°F+ days |
|---|---|---|---|
| Appleton | May 14 | Sep 26 | 45 |
| Eau Claire | May 7 | Sep 27 | 52 |
| Green Bay | May 18 | Sep 23 | 14 |
| Kenosha | May 11 | Oct 4 | 71 |
| La Crosse | May 13 | Sep 26 | 0 |
| Madison | May 10 | Sep 29 | 63 |
| Milwaukee | May 13 | Oct 2 | 63 |
| Oshkosh | May 11 | Sep 30 | 52 |
| Racine | May 24 | Oct 1 | 0 |
| Sheboygan | May 22 | Oct 2 | 49 |
| Wausau | May 17 | Sep 21 | 26 |
What the columns mean
"Open by" is the recommended spring date — two weeks before the city's 7-day mean temperature crosses 61°F, the model's proxy for water approaching the 65°F algae-growth zone. "Close by" is the fall deadline — ten days after the water leaves that zone, capped a week ahead of the local 50% first-freeze date. "80°F+ days" counts days whose normal high reaches 80°F: the length of the true warm-swim season, and the fairest single number for comparing Wisconsin cities against each other.
Every figure comes from each city's own NOAA 1991–2020 normals station (named in its guide's footer), so neighboring cities can legitimately differ by a few days. The season overview linked from each row adds the live water-temperature model and the full-year season bar; the state hubs above carry the step-by-step checklists.
Swim-season length across Wisconsin
The fairest way to compare Wisconsin cities is the number of days with 80°F+ normal highs — the practical warm-swim season. Every bar links to that city's one-page season overview with the live water model.
Wisconsin pool climate at a glance
Long winters and chilly Lake Michigan springs keep Wisconsin openings late, with the northwoods barely warming before an early-September chill closes the short season. In model terms that makes Wisconsin a short-season state. The spread shows up clearly on the local pages: compare Kenosha's pool season with Sheboygan's and the difference is measured in weeks, not days. Neighbors in the index run on their own normals too — see West Virginia and Wyoming for the adjacent calendars.
Wisconsin pool season FAQ
When do pools open in Wisconsin?
Model openings in Wisconsin run from May 7 in Eau Claire to May 24 in Racine, with the statewide median on May 13. Each date is two weeks before that city's 7-day mean temperature crosses 61°F — early enough to start up in algae-cold water.
When should you close a pool in Wisconsin?
The median Wisconsin closing deadline is September 29, and every city's own deadline is capped a week ahead of its NOAA 50% first-freeze date. Closing late and cold beats closing early and warm — cool water holds its winter chemistry far better.
Which Wisconsin city has the longest swim season?
Kenosha leads with 71 days of 80°F+ highs per year, while Racine brings up the rear at 0 days. The chart above ranks every covered city by the same metric.