Pool season · California
Westminster Pool Season: the Year on One Bar
Last updated: July 15, 2026 · dates · water temp
One bar, one year, one Westminster 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.
Each dot on the bar is one week of Westminster's typical year, colored by what the model says that week is for: gray weeks are off-season, hollow teal marks the opening window (February 16–March 9), solid teal is swim season, and hollow amber is the closing window ending December 4. The black marker is today — its position against the colors is the entire executive summary.
The Westminster pool calendar
Opening — target February 23
Open by February 23 — a two-week head start on the March 9 crossing keeps startup chemistry small and beats the local service rush.
Closing — deadline December 4
Hold the cover until November 24, then winterize by December 4, a week ahead of the December 25 freeze normal. Late and cold beats early and warm.
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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 59° | 59° | 60° | 63° | 65° | 68° | 72° | 74° | 75° | 72° | 67° | 60° |
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 Santa Ana Fire Station (7.3 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.