PoolWindow

Pool season · California

San Francisco Pool Season: the Year on One Bar

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

San Francisco'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

The bar compresses San Francisco's whole pool year into one lane rope: gray floats for the off-season, hollow teal for the July 15–August 5 opening window, solid teal for swim weeks, hollow amber for the closing stretch that ends November 6. Wherever the today marker sits, the nearest color change is your next appointment.

The San Francisco pool calendar

July 22open by
November 6close by
080°F+ days
63°Fwater peak

Opening — target July 22

Target July 22; the practical window runs July 15–August 5, and the 7-day mean crosses the 61°F threshold around August 5. Cold-water starts are the cheap ones.

Full opening guide

Closing — deadline November 6

Hold the cover until October 27, then winterize by November 6, a week ahead of the December 25 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 San Francisco water runs about 52°F at its winter floor and 63°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 San Francisco'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 San Francisco Dwtn — ±5°F, see methodology.
JanFebMarAprMayJunJulAugSepOctNovDec
52°53°55°56°57°59°60°61°62°63°60°54°

The curve peaks near 63°F — comfortable-water months here usually involve a heater or a solar cover.

Data: NOAA 1991–2020 climate normals via San Francisco Dwtn (1.4 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.