PoolWindow

Pool season · Texas

San Antonio Pool Season: the Year on One Bar

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

One bar, one year, one San Antonio pool. The season bar below draws everything the model knows — opening window, prime season, closing window — against today's date, with the working details one click away on the opening and closing pages.

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 Antonio's whole pool year into one lane rope: gray floats for the off-season, hollow teal for the February 18–March 11 opening window, solid teal for swim weeks, hollow amber for the closing stretch that ends November 21. Wherever the today marker sits, the nearest color change is your next appointment.

The San Antonio pool calendar

February 25open by
November 21close by
19280°F+ days
85°Fwater peak

Opening — target February 25

Open by February 25 — a two-week head start on the March 11 crossing keeps startup chemistry small and beats the local service rush.

Full opening guide

Closing — deadline November 21

Hold the cover until November 12, then winterize by November 21, a week ahead of the November 28 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 Antonio water runs about 51°F at its winter floor and 85°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 Antonio'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 Antonio Incarnate Word — ±5°F, see methodology.
JanFebMarAprMayJunJulAugSepOctNovDec
52°53°59°66°72°80°83°85°82°75°65°56°

Warmest water typically June–September (peaking near 85°F); heaters and covers shift any month up.

Data: NOAA 1991–2020 climate normals via San Antonio Incarnate Word (3.1 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.