Pool season · California
Tustin Pool Season: the Year on One Bar
Last updated: July 25, 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.
Tustin, CA — 105 swim days a yearReading 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
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.
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.
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.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 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.
Every station tells its own story: compare this curve with Turlock's pool season and Union City's — neighboring normals stations can shift the windows by a week or more. The full ranking lives on the California season index.
Tustin pool season FAQ
When should I open my pool in Tustin, CA?
Open by February 23 — the model places Tustin's 61°F crossing about two weeks later, and every warm day you wait pushes the water toward the 65°F algae zone. The Tustin opening guide has the 12-step sequence.
When should I close my pool in Tustin?
Close by December 4: cool water keeps its winter chemistry, but freeze damage is the hard stop. The Tustin closing guide sequences the work backward from that date.
How long is the swim season in Tustin?
Tustin averages 105 days a year with normal highs of 80°F or better — about 37 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 Tustin?
An unheated pool near Tustin typically peaks around 75°F in high summer and bottoms out near 58°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.
Email me when Tustin hits the closing window
Data: NOAA 1991–2020 climate normals via Santa Ana Fire Station (3.4 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.