PoolWindow

Pool season · California

Pittsburg Pool Season: the Year on One Bar

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

Pittsburg'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

Reading it takes ten seconds: 52 dots, one per week. Solid teal is Pittsburg's swim season; the hollow teal run before it (March 27 to April 17) is when to open; the hollow amber run after is when to close, with November 10 as the deadline; gray is the covered season. Today's marker shows where you stand in that cycle right now.

The Pittsburg pool calendar

April 3open by
November 10close by
14280°F+ days
76°Fwater peak

Opening — target April 3

Target April 3; the practical window runs March 27–April 17, and the 7-day mean crosses the 61°F threshold around April 17. Cold-water starts are the cheap ones.

Full opening guide

Closing — deadline November 10

The window opens October 31 once water leaves the algae zone; the model deadline is November 10, a week ahead of the December 19 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 Pittsburg water runs about 47°F at its winter floor and 76°F at its summer peak.

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

Estimated water temperature by month

This is Pittsburg's typical-year water curve: the same EWMA model as the live widget, run on the 1991–2020 normals instead of this week's weather.

Site-model seasonal water estimates for an unheated in-ground pool near Antioch Pumping Plt #3 — ±5°F, see methodology.
JanFebMarAprMayJunJulAugSepOctNovDec
47°50°55°59°64°70°75°76°74°70°60°51°

The curve peaks near 76°F — comfortable-water months here usually involve a heater or a solar cover.

Data: NOAA 1991–2020 climate normals via Antioch Pumping Plt #3 (8.2 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.