Pool season · Michigan
Wyoming Pool Season: the Year on One Bar
Last updated: July 15, 2026 · dates · water temp
Wyoming'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 Wyoming'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 29 as the deadline; gray is the covered season. Today's marker shows where you stand in that cycle right now.
The Wyoming 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 29
The window opens September 19 once water leaves the algae zone; the model deadline is September 29, a week ahead of the October 10 freeze normal.
Estimated water temperature by month
Monthly averages of the site's water model run on Wyoming'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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 26° | 24° | 30° | 41° | 52° | 64° | 70° | 71° | 66° | 56° | 44° | 34° |
The curve peaks near 72°F — comfortable-water months here usually involve a heater or a solar cover.
Email me when Wyoming hits the closing window
Data: NOAA 1991–2020 climate normals via E Grand Rapids (5.7 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.