Pool season · Colorado
Broomfield Pool Season: the Year on One Bar
Last updated: July 15, 2026 · dates · water temp
This is the one-page view of Broomfield'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.
Reading it takes ten seconds: 52 dots, one per week. Solid teal is Broomfield's swim season; the hollow teal run before it (May 2 to May 23) is when to open; the hollow amber run after is when to close, with October 4 as the deadline; gray is the covered season. Today's marker shows where you stand in that cycle right now.
The Broomfield pool calendar
Opening — target May 9
Target May 9; the practical window runs May 2–May 23, and the 7-day mean crosses the 61°F threshold around May 23. Cold-water starts are the cheap ones.
Closing — deadline October 4
The window opens September 25 once water leaves the algae zone; the model deadline is October 4, a week ahead of the October 11 freeze normal.
Estimated water temperature by month
Monthly averages of the site's water model run on Broomfield'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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 33° | 34° | 39° | 47° | 54° | 65° | 73° | 75° | 70° | 58° | 46° | 36° |
The curve peaks near 75°F — comfortable-water months here usually involve a heater or a solar cover.
Email me when Broomfield hits the closing window
Data: NOAA 1991–2020 climate normals via Northglenn (4.3 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.