Pool season · California
Corona Pool Season: the Year on One Bar
Last updated: July 15, 2026 · dates · water temp
This is the one-page view of Corona'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 Corona's swim season; the hollow teal run before it (March 14 to April 4) is when to open; the hollow amber run after is when to close, with November 24 as the deadline; gray is the covered season. Today's marker shows where you stand in that cycle right now.
The Corona pool calendar
Opening — target March 21
Target March 21; the practical window runs March 14–April 4, and the 7-day mean crosses the 61°F threshold around April 4. Cold-water starts are the cheap ones.
Closing — deadline November 24
The window opens November 14 once water leaves the algae zone; the model deadline is November 24, a week ahead of the December 19 freeze normal.
Estimated water temperature by month
Monthly averages of the site's water model run on Corona'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° | 66° | 70° | 76° | 79° | 79° | 73° | 65° | 57° |
Warmest water typically August–September (peaking near 80°F); heaters and covers shift any month up.
Email me when Corona hits the closing window
Data: NOAA 1991–2020 climate normals via Chino Airport (8.8 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.