Pool season · Michigan
Detroit Pool Season: the Year on One Bar
Last updated: July 15, 2026 · dates · water temp
One bar, one year, one Detroit 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.
Each dot on the bar is one week of Detroit's typical year, colored by what the model says that week is for: gray weeks are off-season, hollow teal marks the opening window (May 1–May 22), solid teal is swim season, and hollow amber is the closing window ending October 6. The black marker is today — its position against the colors is the entire executive summary.
The Detroit pool calendar
Opening — target May 8
Open by May 8 — a two-week head start on the May 22 crossing keeps startup chemistry small and beats the local service rush.
Closing — deadline October 6
Hold the cover until September 26, then winterize by October 6, a week ahead of the October 25 freeze normal. Late and cold beats early and warm.
Estimated water temperature by month
Monthly averages of the site's water model run on Detroit's own normals — the shape of a typical year, not a forecast. The widget above shows where the current year actually sits.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 28° | 26° | 32° | 43° | 54° | 65° | 73° | 73° | 69° | 59° | 47° | 36° |
The curve peaks near 74°F — comfortable-water months here usually involve a heater or a solar cover.
Email me when Detroit hits the closing window
Data: NOAA 1991–2020 climate normals via Dearborn #2 (4.4 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.