PoolWindow

Pool season · California

West Covina Pool Season: the Year on One Bar

Last updated: July 25, 2026 · dates · water temp

West Covina's whole pool calendar, condensed: when the water warms, when it cools, and where today falls between those edges. Use the opening guide and closing guide for the step-by-step work; keep this page for the dates.

Courtyard swimming pool at dawn in a temperate climateWest Covina, CA — 144 swim days a year
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 West Covina'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 7–March 28), solid teal is swim season, and hollow amber is the closing window ending November 23. The black marker is today — its position against the colors is the entire executive summary.

The West Covina pool calendar

March 14open by
November 23close by
14480°F+ days
78°Fwater peak

Opening — target March 14

Target March 14; the practical window runs March 7–March 28, and the 7-day mean crosses the 61°F threshold around March 28. Cold-water starts are the cheap ones.

Full opening guide

Closing — deadline November 23

The window opens November 13 once water leaves the algae zone; the model deadline is November 23, a week ahead of the December 28 freeze normal.

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 West Covina water runs about 54°F at its winter floor and 78°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 West Covina's own normals — the shape of a typical year, not a forecast. The widget above shows where the current year actually sits.

40°50°60°70°80°90°JanFebMarAprMayJunJulAugSepOctNovDec65° algae zone58° swimmable startopen Mar 14close Nov 2378°F peak54°F floor
Site-model seasonal water estimates for an unheated in-ground pool near Pomona/fairplex — ±5°F, see methodology.
JanFebMarAprMayJunJulAugSepOctNovDec
55°56°58°61°65°68°74°77°77°71°64°56°

The curve peaks near 78°F — comfortable-water months here usually involve a heater or a solar cover.

Every station tells its own story: compare this curve with Watsonville's pool season and Westminster's — neighboring normals stations can shift the windows by a week or more. The full ranking lives on the California season index.

West Covina pool season FAQ

When should I open my pool in West Covina, CA?

Open by March 14 — the model places West Covina's 61°F crossing about two weeks later, and every warm day you wait pushes the water toward the 65°F algae zone. The West Covina opening guide has the 12-step sequence.

When should I close my pool in West Covina?

Close by November 23: cool water keeps its winter chemistry, but freeze damage is the hard stop. The West Covina closing guide sequences the work backward from that date.

How long is the swim season in West Covina?

West Covina averages 144 days a year with normal highs of 80°F or better — about 18 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 West Covina?

An unheated pool near West Covina typically peaks around 78°F in high summer and bottoms out near 54°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.

Data: NOAA 1991–2020 climate normals via Pomona/fairplex (8.5 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.