Pool season · California
Fullerton Pool Season: the Year on One Bar
Last updated: July 15, 2026 · dates · water temp
One bar, one year, one Fullerton 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 Fullerton's whole pool year into one lane rope: gray floats for the off-season, hollow teal for the February 20–March 13 opening window, solid teal for swim weeks, hollow amber for the closing stretch that ends November 30. Wherever the today marker sits, the nearest color change is your next appointment.
The Fullerton pool calendar
Opening — target February 27
Target February 27; the practical window runs February 20–March 13, and the 7-day mean crosses the 61°F threshold around March 13. Cold-water starts are the cheap ones.
Closing — deadline November 30
The window opens November 20 once water leaves the algae zone; the model deadline is November 30, a week ahead of the December 25 freeze normal.
Estimated water temperature by month
This is Fullerton'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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 57° | 58° | 60° | 63° | 66° | 69° | 74° | 76° | 76° | 72° | 66° | 59° |
The curve peaks near 77°F — comfortable-water months here usually involve a heater or a solar cover.
Email me when Fullerton hits the closing window
Data: NOAA 1991–2020 climate normals via Fullerton Municipal Airport (3.0 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.