Pool season · California
Corona Pool Season: the Year on One Bar
Last updated: July 25, 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.
Corona, CA — 183 swim days a yearReading 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.
Every station tells its own story: compare this curve with Concord's pool season and Costa Mesa's — neighboring normals stations can shift the windows by a week or more. The full ranking lives on the California season index.
Corona pool season FAQ
When should I open my pool in Corona, CA?
Open by March 21 — the model places Corona's 61°F crossing about two weeks later, and every warm day you wait pushes the water toward the 65°F algae zone. The Corona opening guide has the 12-step sequence.
When should I close my pool in Corona?
Close by November 24: cool water keeps its winter chemistry, but freeze damage is the hard stop. The Corona closing guide sequences the work backward from that date.
How long is the swim season in Corona?
Corona averages 183 days a year with normal highs of 80°F or better — about 11 days earlier than the California median. The California season index ranks all 147 covered cities by the same metric.
How warm does pool water get in Corona?
An unheated pool near Corona typically peaks around 80°F in high summer and bottoms out near 55°F in winter, spending roughly 2 months at or above the 78°F comfort line most swimmers prefer. The month-by-month curve above shows the whole cycle; the methodology page explains the ±5°F error bars.
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.