PoolWindow

Pool season · Texas

Round Rock Pool Season: the Year on One Bar

Last updated: July 25, 2026 · dates · water temp

This is the one-page view of Round Rock's pool year: both model windows, the estimated water-temperature curve, and today's live position on the season bar. The detailed checklists live on the opening and closing guides; this page is the calendar you check between them.

Resort pool at dusk in a hot, long-season climateRound Rock, TX — 177 swim days a year
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 Round Rock's swim season; the hollow teal run before it (February 28 to March 21) is when to open; the hollow amber run after is when to close, with November 13 as the deadline; gray is the covered season. Today's marker shows where you stand in that cycle right now.

The Round Rock pool calendar

March 7open by
November 13close by
17780°F+ days
85°Fwater peak

Opening — target March 7

Open by March 7 — a two-week head start on the March 21 crossing keeps startup chemistry small and beats the local service rush.

Full opening guide

Closing — deadline November 13

Hold the cover until November 5, then winterize by November 13, a week ahead of the November 20 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 Round Rock water runs about 48°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 Round Rock'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.

40°50°60°70°80°90°100°JanFebMarAprMayJunJulAugSepOctNovDec65° algae zone58° swimmable startopen Mar 7close Nov 1385°F peak48°F floor
Site-model seasonal water estimates for an unheated in-ground pool near Austin Great Hills — ±5°F, see methodology.
JanFebMarAprMayJunJulAugSepOctNovDec
48°51°57°64°70°79°83°85°81°74°63°53°

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 Richardson's pool season and Rowlett's — neighboring normals stations can shift the windows by a week or more. The full ranking lives on the Texas season index.

Round Rock pool season FAQ

When should I open my pool in Round Rock, TX?

Target March 7. That date backs off two weeks from the day Round Rock's 7-day mean temperature reaches 61°F, so you start up in cold, algae-resistant water. Work the full checklist in the Round Rock opening guide.

When should I close my pool in Round Rock?

The closing deadline is November 13 — late enough that the water has cooled out of the algae zone, early enough to beat Round Rock's first-freeze normal by about a week. See the Round Rock closing guide for the winterizing steps.

How long is the swim season in Round Rock?

Round Rock averages 177 days a year with normal highs of 80°F or better — right on the statewide median. The Texas season index ranks all 68 covered cities by the same metric.

How warm does pool water get in Round Rock?

An unheated pool near Round Rock typically peaks around 85°F in high summer and bottoms out near 48°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.

Data: NOAA 1991–2020 climate normals via Austin Great Hills (9.9 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.