Pool season · California
Pomona Pool Season: the Year on One Bar
Last updated: July 15, 2026 · dates · water temp
One bar, one year, one Pomona 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.
Reading it takes ten seconds: 52 dots, one per week. Solid teal is Pomona's swim season; the hollow teal run before it (March 7 to March 28) is when to open; the hollow amber run after is when to close, with November 23 as the deadline; gray is the covered season. Today's marker shows where you stand in that cycle right now.
The Pomona pool calendar
Opening — target March 14
Open by March 14 — a two-week head start on the March 28 crossing keeps startup chemistry small and beats the local service rush.
Closing — deadline November 23
The window opens November 13 once water leaves the algae zone; the model deadline is November 23, a week ahead of the December 28 freeze normal.
Estimated water temperature by month
Monthly averages of the site's water model run on Pomona'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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 55° | 56° | 58° | 61° | 65° | 68° | 74° | 77° | 77° | 71° | 64° | 56° |
The curve peaks near 78°F — comfortable-water months here usually involve a heater or a solar cover.
Email me when Pomona hits the closing window
Data: NOAA 1991–2020 climate normals via Pomona/fairplex (1.6 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.