Pool season · California
Perris Pool Season: the Year on One Bar
Last updated: July 25, 2026 · dates · water temp
This is the one-page view of Perris's pool year: both model windows, the estimated water-temperature curve, and today's live position on the season bar. The detailed checklists live on the opening and closing guides; this page is the calendar you check between them.
Perris, CA — 173 swim days a yearEach dot on the bar is one week of Perris's typical year, colored by what the model says that week is for: gray weeks are off-season, hollow teal marks the opening window (March 13–April 3), solid teal is swim season, and hollow amber is the closing window ending November 21. The black marker is today — its position against the colors is the entire executive summary.
The Perris pool calendar
Opening — target March 20
Open by March 20 — a two-week head start on the April 3 crossing keeps startup chemistry small and beats the local service rush.
Closing — deadline November 21
Hold the cover until November 11, then winterize by November 21, a week ahead of the December 18 freeze normal. Late and cold beats early and warm.
Estimated water temperature by month
Monthly averages of the site's water model run on Perris'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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 53° | 54° | 57° | 61° | 65° | 71° | 78° | 81° | 80° | 73° | 64° | 55° |
Warmest water typically July–September (peaking near 82°F); heaters and covers shift any month up.
Every station tells its own story: compare this curve with Pasadena's pool season and Pittsburg's — neighboring normals stations can shift the windows by a week or more. The full ranking lives on the California season index.
Perris pool season FAQ
When should I open my pool in Perris, CA?
The site model recommends opening by March 20 — about two weeks before Perris'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 Perris opening guide.
When should I close my pool in Perris?
Winterize by November 21. The model holds the deadline a week ahead of Perris's NOAA 50% first-freeze date, so the plumbing is protected before the first hard night. The full sequence is in the Perris closing guide.
How long is the swim season in Perris?
Perris averages 173 days a year with normal highs of 80°F or better — about 12 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 Perris?
An unheated pool near Perris typically peaks around 82°F in high summer and bottoms out near 52°F in winter, spending roughly 2 months at or above the 78°F comfort line most swimmers prefer. The month-by-month curve above shows the whole cycle; the methodology page explains the ±5°F error bars.
Email me when Perris hits the closing window
Data: NOAA 1991–2020 climate normals via Elsinore (10.1 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.