Pool season · Colorado
Centennial Pool Season: the Year on One Bar
Last updated: July 15, 2026 · dates · water temp
One bar, one year, one Centennial 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.
The bar compresses Centennial's whole pool year into one lane rope: gray floats for the off-season, hollow teal for the May 9–May 30 opening window, solid teal for swim weeks, hollow amber for the closing stretch that ends September 30. Wherever the today marker sits, the nearest color change is your next appointment.
The Centennial pool calendar
Opening — target May 16
Target May 16; the practical window runs May 9–May 30, and the 7-day mean crosses the 61°F threshold around May 30. Cold-water starts are the cheap ones.
Closing — deadline September 30
Hold the cover until September 20, then winterize by September 30, a week ahead of the October 8 freeze normal. Late and cold beats early and warm.
Estimated water temperature by month
This is Centennial'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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 31° | 32° | 37° | 44° | 51° | 62° | 71° | 72° | 67° | 56° | 44° | 34° |
The curve peaks near 73°F — comfortable-water months here usually involve a heater or a solar cover.
Email me when Centennial hits the closing window
Data: NOAA 1991–2020 climate normals via Denver Centennial Airport (1.8 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.