Pool season · Wisconsin
Milwaukee Pool Season: the Year on One Bar
Last updated: July 25, 2026 · dates · water temp
This is the one-page view of Milwaukee's pool year: both model windows, the estimated water-temperature curve, and today's live position on the season bar. The detailed checklists live on the opening and closing guides; this page is the calendar you check between them.
Milwaukee, WI — 63 swim days a yearThe bar compresses Milwaukee's whole pool year into one lane rope: gray floats for the off-season, hollow teal for the May 6–May 27 opening window, solid teal for swim weeks, hollow amber for the closing stretch that ends October 2. Wherever the today marker sits, the nearest color change is your next appointment.
The Milwaukee pool calendar
Opening — target May 13
Open by May 13 — a two-week head start on the May 27 crossing keeps startup chemistry small and beats the local service rush.
Closing — deadline October 2
The window opens September 22 once water leaves the algae zone; the model deadline is October 2, a week ahead of the October 18 freeze normal.
Estimated water temperature by month
This is Milwaukee'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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 24° | 22° | 31° | 41° | 53° | 63° | 72° | 72° | 68° | 57° | 44° | 32° |
The curve peaks near 73°F — comfortable-water months here usually involve a heater or a solar cover.
Every station tells its own story: compare this curve with Madison's pool season and Oshkosh's — neighboring normals stations can shift the windows by a week or more. The full ranking lives on the Wisconsin season index.
Milwaukee pool season FAQ
When should I open my pool in Milwaukee, WI?
Open by May 13 — the model places Milwaukee's 61°F crossing about two weeks later, and every warm day you wait pushes the water toward the 65°F algae zone. The Milwaukee opening guide has the 12-step sequence.
When should I close my pool in Milwaukee?
Close by October 2: cool water keeps its winter chemistry, but freeze damage is the hard stop. The Milwaukee closing guide sequences the work backward from that date.
How long is the swim season in Milwaukee?
Milwaukee averages 63 days a year with normal highs of 80°F or better — right on the statewide median. The Wisconsin season index ranks all 11 covered cities by the same metric.
How warm does pool water get in Milwaukee?
An unheated pool near Milwaukee typically peaks around 73°F in high summer and bottoms out near 21°F in winter, never quite reaching the 78°F comfort line without a heater or solar cover. The month-by-month curve above shows the whole cycle; the methodology page explains the ±5°F error bars.
Email me when Milwaukee hits the closing window
Data: NOAA 1991–2020 climate normals via Mt Mary College (3.2 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.