PoolWindow

Pool season · California

Chino Hills Pool Season: the Year on One Bar

Last updated: July 25, 2026 · dates · water temp

This is the one-page view of Chino Hills'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.

Resort pool at dusk in a hot, long-season climateChino Hills, CA — 183 swim days a year
J F M A M J J A S O N D today (build date)

off-season opening window swim season closing window

Reading it takes ten seconds: 52 dots, one per week. Solid teal is Chino Hills'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 Chino Hills pool calendar

March 21open by
November 24close by
18380°F+ days
80°Fwater peak

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.

Full opening guide

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.

Full closing guide

Where the water sits today

SEASONAL VIEW

Estimated unheated pool water temp (site model, ±5°F). The live estimate loads in your browser from Open-Meteo air temperatures; in a typical year Chino Hills water runs about 55°F at its winter floor and 80°F at its summer peak.

40 45 50 55 60 65 70 75 80 85 58 open 65 algae

Estimated water temperature by month

This is Chino Hills'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.

40°50°60°70°80°90°JanFebMarAprMayJunJulAugSepOctNovDec65° algae zone58° swimmable startopen Mar 21close Nov 2480°F peak55°F floor
Site-model seasonal water estimates for an unheated in-ground pool near Chino Airport — ±5°F, see methodology.
JanFebMarAprMayJunJulAugSepOctNovDec
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 Chino's pool season and Chula Vista's — neighboring normals stations can shift the windows by a week or more. The full ranking lives on the California season index.

Chino Hills pool season FAQ

When should I open my pool in Chino Hills, CA?

Open by March 21 — the model places Chino Hills's 61°F crossing about two weeks later, and every warm day you wait pushes the water toward the 65°F algae zone. The Chino Hills opening guide has the 12-step sequence.

When should I close my pool in Chino Hills?

Close by November 24: cool water keeps its winter chemistry, but freeze damage is the hard stop. The Chino Hills closing guide sequences the work backward from that date.

How long is the swim season in Chino Hills?

Chino Hills 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 Chino Hills?

An unheated pool near Chino Hills 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.

Data: NOAA 1991–2020 climate normals via Chino Airport (5.4 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.