PoolWindow

Pool season · California

Dublin Pool Season: the Year on One Bar

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

One bar, one year, one Dublin 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.

Courtyard swimming pool at dawn in a temperate climateDublin, CA — 129 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

The bar compresses Dublin's whole pool year into one lane rope: gray floats for the off-season, hollow teal for the April 12–May 3 opening window, solid teal for swim weeks, hollow amber for the closing stretch that ends November 3. Wherever the today marker sits, the nearest color change is your next appointment.

The Dublin pool calendar

April 19open by
November 3close by
12980°F+ days
73°Fwater peak

Opening — target April 19

Target April 19; the practical window runs April 12–May 3, and the 7-day mean crosses the 61°F threshold around May 3. Cold-water starts are the cheap ones.

Full opening guide

Closing — deadline November 3

The window opens October 24 once water leaves the algae zone; the model deadline is November 3, a week ahead of the December 2 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 Dublin water runs about 47°F at its winter floor and 73°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 Dublin'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°JanFebMarAprMayJunJulAugSepOctNovDec65° algae zone58° swimmable startopen Apr 19close Nov 373°F peak47°F floor
Site-model seasonal water estimates for an unheated in-ground pool near Livermore — ±5°F, see methodology.
JanFebMarAprMayJunJulAugSepOctNovDec
47°49°53°56°61°66°72°73°72°67°58°50°

The curve peaks near 73°F — comfortable-water months here usually involve a heater or a solar cover.

Every station tells its own story: compare this curve with Downey's pool season and East Los Angeles's — neighboring normals stations can shift the windows by a week or more. The full ranking lives on the California season index.

Dublin pool season FAQ

When should I open my pool in Dublin, CA?

The site model recommends opening by April 19 — about two weeks before Dublin's 7-day mean temperature crosses 61°F, while the water is still too cold for algae. The step-by-step sequence is in the Dublin opening guide.

When should I close my pool in Dublin?

Winterize by November 3. The model holds the deadline a week ahead of Dublin's NOAA 50% first-freeze date, so the plumbing is protected before the first hard night. The full sequence is in the Dublin closing guide.

How long is the swim season in Dublin?

Dublin averages 129 days a year with normal highs of 80°F or better — about 18 days later than the California median. The California season index ranks all 147 covered cities by the same metric.

How warm does pool water get in Dublin?

An unheated pool near Dublin typically peaks around 73°F in high summer and bottoms out near 47°F in winter, never quite reaching the 78°F comfort line without a heater or solar cover. 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 Livermore (4.8 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.