Pool season · Texas
San Antonio Pool Season: the Year on One Bar
Last updated: July 25, 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.
San Antonio, TX — 192 swim days a yearThe 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
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.
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.
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.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 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.
Every station tells its own story: compare this curve with San Angelo's pool season and San Marcos's — neighboring normals stations can shift the windows by a week or more. The full ranking lives on the Texas season index.
San Antonio pool season FAQ
When should I open my pool in San Antonio, TX?
Target February 25. That date backs off two weeks from the day San Antonio's 7-day mean temperature reaches 61°F, so you start up in cold, algae-resistant water. Work the full checklist in the San Antonio opening guide.
When should I close my pool in San Antonio?
The closing deadline is November 21 — late enough that the water has cooled out of the algae zone, early enough to beat San Antonio's first-freeze normal by about a week. See the San Antonio closing guide for the winterizing steps.
How long is the swim season in San Antonio?
San Antonio averages 192 days a year with normal highs of 80°F or better — about 11 days earlier than the Texas median. The Texas season index ranks all 68 covered cities by the same metric.
How warm does pool water get in San Antonio?
An unheated pool near San Antonio typically peaks around 85°F in high summer and bottoms out near 51°F in winter, spending roughly 4 months at or above the 78°F comfort line most swimmers prefer. The month-by-month curve above shows the whole cycle; the methodology page explains the ±5°F error bars.
Email me when San Antonio hits the closing window
Data: NOAA 1991–2020 climate normals via San Antonio Incarnate Word (3.1 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.