Pool season · California
Whittier Pool Season: the Year on One Bar
Last updated: July 25, 2026 · dates · water temp
One bar, one year, one Whittier 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.
Whittier, CA — 120 swim days a yearReading it takes ten seconds: 52 dots, one per week. Solid teal is Whittier's swim season; the hollow teal run before it (February 20 to March 13) is when to open; the hollow amber run after is when to close, with November 30 as the deadline; gray is the covered season. Today's marker shows where you stand in that cycle right now.
The Whittier pool calendar
Opening — target February 27
Target February 27; the practical window runs February 20–March 13, and the 7-day mean crosses the 61°F threshold around March 13. Cold-water starts are the cheap ones.
Closing — deadline November 30
Hold the cover until November 20, then winterize by November 30, a week ahead of the January 2 freeze normal. Late and cold beats early and warm.
Estimated water temperature by month
This is Whittier'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.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 57° | 58° | 60° | 63° | 66° | 69° | 74° | 76° | 76° | 72° | 66° | 59° |
The curve peaks near 77°F — comfortable-water months here usually involve a heater or a solar cover.
Every station tells its own story: compare this curve with Westminster's pool season and Yorba Linda's — neighboring normals stations can shift the windows by a week or more. The full ranking lives on the California season index.
Whittier pool season FAQ
When should I open my pool in Whittier, CA?
The site model recommends opening by February 27 — about two weeks before Whittier'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 Whittier opening guide.
When should I close my pool in Whittier?
Winterize by November 30. The model holds the deadline a week ahead of Whittier's NOAA 50% first-freeze date, so the plumbing is protected before the first hard night. The full sequence is in the Whittier closing guide.
How long is the swim season in Whittier?
Whittier averages 120 days a year with normal highs of 80°F or better — about 33 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 Whittier?
An unheated pool near Whittier typically peaks around 77°F in high summer and bottoms out near 57°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 Whittier hits the closing window
Data: NOAA 1991–2020 climate normals via Fullerton Municipal Airport (7.0 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.