PoolWindow

Pool season · California

Perris Pool Season: the Year on One Bar

Last updated: July 15, 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.

J F M A M J J A S O N D today (build date)

off-season opening window swim season closing window

Each 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

March 20open by
November 21close by
17380°F+ days
82°Fwater peak

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.

Full opening guide

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.

Full closing guide

Where the water sits today

SEASONAL VIEW

Estimated unheated pool water temp (site model, ±5°F). The live estimate loads in your browser from Open-Meteo air temperatures; in a typical year Perris water runs about 52°F at its winter floor and 82°F at its summer peak.

40 45 50 55 60 65 70 75 80 85 58 open 65 algae

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.

Site-model seasonal water estimates for an unheated in-ground pool near Elsinore — ±5°F, see methodology.
JanFebMarAprMayJunJulAugSepOctNovDec
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.

Data: NOAA 1991–2020 climate normals via Elsinore (10.1 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.