Pool season · Michigan
Warren Pool Season: the Year on One Bar
Last updated: July 15, 2026 · dates · water temp
Warren's whole pool calendar, condensed: when the water warms, when it cools, and where today falls between those edges. Use the opening guide and closing guide for the step-by-step work; keep this page for the dates.
Reading it takes ten seconds: 52 dots, one per week. Solid teal is Warren's swim season; the hollow teal run before it (April 29 to May 20) is when to open; the hollow amber run after is when to close, with October 6 as the deadline; gray is the covered season. Today's marker shows where you stand in that cycle right now.
The Warren pool calendar
Opening — target May 6
Target May 6; the practical window runs April 29–May 20, and the 7-day mean crosses the 61°F threshold around May 20. Cold-water starts are the cheap ones.
Closing — deadline October 6
Hold the cover until September 26, then winterize by October 6, a week ahead of the October 31 freeze normal. Late and cold beats early and warm.
Estimated water temperature by month
This is Warren'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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 28° | 26° | 32° | 43° | 54° | 66° | 73° | 74° | 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 Warren hits the closing window
Data: NOAA 1991–2020 climate normals via Detroit City Airport (5.9 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.