PoolWindow

Pool season · California

Concord Pool Season: the Year on One Bar

Last updated: July 15, 2026 · dates · water temp

Concord'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.

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 Concord's typical year, colored by what the model says that week is for: gray weeks are off-season, hollow teal marks the opening window (April 1–April 22), solid teal is swim season, and hollow amber is the closing window ending November 9. The black marker is today — its position against the colors is the entire executive summary.

The Concord pool calendar

April 8open by
November 9close by
13580°F+ days
74°Fwater peak

Opening — target April 8

Open by April 8 — a two-week head start on the April 22 crossing keeps startup chemistry small and beats the local service rush.

Full opening guide

Closing — deadline November 9

The window opens October 30 once water leaves the algae zone; the model deadline is November 9, a week ahead of the December 14 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 Concord water runs about 49°F at its winter floor and 74°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 Concord'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 Concord Buchanan Field — ±5°F, see methodology.
JanFebMarAprMayJunJulAugSepOctNovDec
49°51°55°58°63°68°73°74°73°69°60°52°

The curve peaks near 74°F — comfortable-water months here usually involve a heater or a solar cover.

Data: NOAA 1991–2020 climate normals via Concord Buchanan Field (3.2 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.