Pool season · Colorado
Westminster Pool Season: the Year on One Bar
Last updated: July 15, 2026 · dates · water temp
Westminster'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 Westminster'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 Westminster pool calendar
Opening — target May 9
Open by May 9 — a two-week head start on the May 23 crossing keeps startup chemistry small and beats the local service rush.
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
This is Westminster'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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 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 Westminster hits the closing window
Data: NOAA 1991–2020 climate normals via Northglenn (2.8 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.