Pool season · Wisconsin
Oshkosh Pool Season: the Year on One Bar
Last updated: July 15, 2026 · dates · water temp
One bar, one year, one Oshkosh pool. The season bar below draws everything the model knows — opening window, prime season, closing window — against today's date, with the working details one click away on the opening and closing pages.
Reading it takes ten seconds: 52 dots, one per week. Solid teal is Oshkosh's swim season; the hollow teal run before it (May 4 to May 25) is when to open; the hollow amber run after is when to close, with September 30 as the deadline; gray is the covered season. Today's marker shows where you stand in that cycle right now.
The Oshkosh pool calendar
Opening — target May 11
Target May 11; the practical window runs May 4–May 25, and the 7-day mean crosses the 61°F threshold around May 25. Cold-water starts are the cheap ones.
Closing — deadline September 30
The window opens September 20 once water leaves the algae zone; the model deadline is September 30, a week ahead of the October 20 freeze normal.
Estimated water temperature by month
This is Oshkosh's typical-year water curve: the same EWMA model as the live widget, run on the 1991–2020 normals instead of this week's weather.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 20° | 19° | 27° | 39° | 52° | 64° | 71° | 72° | 67° | 56° | 43° | 30° |
The curve peaks near 72°F — comfortable-water months here usually involve a heater or a solar cover.
Email me when Oshkosh hits the closing window
Data: NOAA 1991–2020 climate normals via Oshkosh (0.2 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.