Pool season · Texas
Arlington Pool Season: the Year on One Bar
Last updated: July 25, 2026 · dates · water temp
This is the one-page view of Arlington'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.
Arlington, TX — 166 swim days a yearEach dot on the bar is one week of Arlington's typical year, colored by what the model says that week is for: gray weeks are off-season, hollow teal marks the opening window (March 3–March 24), solid teal is swim season, and hollow amber is the closing window ending November 12. The black marker is today — its position against the colors is the entire executive summary.
The Arlington pool calendar
Opening — target March 10
Open by March 10 — a two-week head start on the March 24 crossing keeps startup chemistry small and beats the local service rush.
Closing — deadline November 12
The window opens November 2 once water leaves the algae zone; the model deadline is November 12, a week ahead of the November 21 freeze normal.
Estimated water temperature by month
Monthly averages of the site's water model run on Arlington's own normals — the shape of a typical year, not a forecast. The widget above shows where the current year actually sits.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 47° | 49° | 55° | 63° | 70° | 79° | 84° | 86° | 82° | 73° | 62° | 52° |
Warmest water typically June–September (peaking near 86°F); heaters and covers shift any month up.
Every station tells its own story: compare this curve with Amarillo's pool season and Atascocita's — neighboring normals stations can shift the windows by a week or more. The full ranking lives on the Texas season index.
Arlington pool season FAQ
When should I open my pool in Arlington, TX?
Target March 10. That date backs off two weeks from the day Arlington's 7-day mean temperature reaches 61°F, so you start up in cold, algae-resistant water. Work the full checklist in the Arlington opening guide.
When should I close my pool in Arlington?
The closing deadline is November 12 — late enough that the water has cooled out of the algae zone, early enough to beat Arlington's first-freeze normal by about a week. See the Arlington closing guide for the winterizing steps.
How long is the swim season in Arlington?
Arlington averages 166 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 Arlington?
An unheated pool near Arlington typically peaks around 86°F in high summer and bottoms out near 47°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 Arlington hits the closing window
Data: NOAA 1991–2020 climate normals via Arlington Municipal Airport (3.1 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.