Pool season · California
Norwalk Pool Season: the Year on One Bar
Last updated: July 25, 2026 · dates · water temp
One bar, one year, one Norwalk 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.
Norwalk, CA — 120 swim days a yearReading it takes ten seconds: 52 dots, one per week. Solid teal is Norwalk'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 Norwalk pool calendar
Opening — target February 27
Open by February 27 — a two-week head start on the March 13 crossing keeps startup chemistry small and beats the local service rush.
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 Norwalk'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 Newport Beach's pool season and Oakland's — neighboring normals stations can shift the windows by a week or more. The full ranking lives on the California season index.
Norwalk pool season FAQ
When should I open my pool in Norwalk, CA?
Target February 27. That date backs off two weeks from the day Norwalk's 7-day mean temperature reaches 61°F, so you start up in cold, algae-resistant water. Work the full checklist in the Norwalk opening guide.
When should I close my pool in Norwalk?
The closing deadline is November 30 — late enough that the water has cooled out of the algae zone, early enough to beat Norwalk's first-freeze normal by about a week. See the Norwalk closing guide for the winterizing steps.
How long is the swim season in Norwalk?
Norwalk 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 Norwalk?
An unheated pool near Norwalk 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 Norwalk hits the closing window
Data: NOAA 1991–2020 climate normals via Fullerton Municipal Airport (6.5 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.