PoolWindow

Pool season · California

Tustin Pool Season: the Year on One Bar

Last updated: July 15, 2026 · dates · water temp

Tustin's whole pool calendar, condensed: when the water warms, when it cools, and where today falls between those edges. Use the opening guide and closing guide for the step-by-step work; keep this page for the dates.

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 Tustin's swim season; the hollow teal run before it (February 16 to March 9) is when to open; the hollow amber run after is when to close, with December 4 as the deadline; gray is the covered season. Today's marker shows where you stand in that cycle right now.

The Tustin pool calendar

February 23open by
December 4close by
10580°F+ days
75°Fwater peak

Opening — target February 23

Open by February 23 — a two-week head start on the March 9 crossing keeps startup chemistry small and beats the local service rush.

Full opening guide

Closing — deadline December 4

The window opens November 24 once water leaves the algae zone; the model deadline is December 4, a week ahead of the December 25 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 Tustin water runs about 58°F at its winter floor and 75°F at its summer peak.

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

Estimated water temperature by month

Monthly averages of the site's water model run on Tustin's own normals — the shape of a typical year, not a forecast. The widget above shows where the current year actually sits.

Site-model seasonal water estimates for an unheated in-ground pool near Santa Ana Fire Station — ±5°F, see methodology.
JanFebMarAprMayJunJulAugSepOctNovDec
59°59°60°63°65°68°72°74°75°72°67°60°

The curve peaks near 75°F — comfortable-water months here usually involve a heater or a solar cover.

Data: NOAA 1991–2020 climate normals via Santa Ana Fire Station (3.4 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.