Pool season · California
Chico Pool Season: the Year on One Bar
Last updated: July 25, 2026 · dates · water temp
One bar, one year, one Chico 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.
Chico, CA — 158 swim days a yearThe bar compresses Chico's whole pool year into one lane rope: gray floats for the off-season, hollow teal for the April 3–April 24 opening window, solid teal for swim weeks, hollow amber for the closing stretch that ends November 1. Wherever the today marker sits, the nearest color change is your next appointment.
The Chico pool calendar
Opening — target April 10
Target April 10; the practical window runs April 3–April 24, and the 7-day mean crosses the 61°F threshold around April 24. Cold-water starts are the cheap ones.
Closing — deadline November 1
Hold the cover until October 22, then winterize by November 1, a week ahead of the November 17 freeze normal. Late and cold beats early and warm.
Estimated water temperature by month
Monthly averages of the site's water model run on Chico'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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 46° | 48° | 52° | 57° | 63° | 71° | 76° | 78° | 75° | 69° | 57° | 49° |
Warmest water typically August–August (peaking near 78°F); heaters and covers shift any month up.
Every station tells its own story: compare this curve with Castro Valley's pool season and Chino's — neighboring normals stations can shift the windows by a week or more. The full ranking lives on the California season index.
Chico pool season FAQ
When should I open my pool in Chico, CA?
Target April 10. That date backs off two weeks from the day Chico's 7-day mean temperature reaches 61°F, so you start up in cold, algae-resistant water. Work the full checklist in the Chico opening guide.
When should I close my pool in Chico?
The closing deadline is November 1 — late enough that the water has cooled out of the algae zone, early enough to beat Chico's first-freeze normal by about a week. See the Chico closing guide for the winterizing steps.
How long is the swim season in Chico?
Chico averages 158 days a year with normal highs of 80°F or better — about 9 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 Chico?
An unheated pool near Chico typically peaks around 78°F in high summer and bottoms out near 46°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 Chico hits the closing window
Data: NOAA 1991–2020 climate normals via Chico University Farm (4.6 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.