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Pool closing · Texas

When to Close Your Pool in Arlington, TX: Deadline, Window & Checklist

Last updated: July 15, 2026 · Model window year: 2026 · dates · checklist · FAQ

Two dates decide a Arlington closing: November 2, when the 7-day mean drops back through 61°F and the water goes algae-quiet, and November 12, the model deadline set a safe week ahead of the November 21 first-freeze normal. Everything on this page — live water estimate, window, winterizing sequence — exists to land you between them.

Live water estimate

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 Arlington water runs about 47°F at its winter floor and 86°F at its summer peak.

40 45 50 55 60 65 70 75 80 85 58 open 65 algae

Arlington closing dates at a glance

Site model of NOAA 1991–2020 daily normals for Arlington Municipal Airport (3.1 mi from Arlington city center). Dates are typical-year guidance, not forecasts.
Closing windowNovember 2 – November 12
Close by (deadline)November 12
First freeze, 50% probabilityNovember 21
Open by (recommended)March 10
Opening windowMarch 3 – March 24
61°F crossing (7-day mean)March 24
Swim-season length (80°F+ days)166 days
NOAA normals stationArlington Municipal Airport · 3.1 mi · 630 ft

A classic four-season pool calendar: open early into cold water, close late into cold water, and Arlington's 166 days of prime swimming sit safely in between.

Put dates aside and follow the water: the Arlington curve says roughly 65°F by mid-April, 81°F by mid-June, 86°F in mid-August, then back down through 71°F in mid-October. The summer ceiling sits near 86°F, and every window above is just a line drawn on this curve.

The 12-step Arlington winterizing checklist

A closing is a plumbing project with a chemistry warm-up. Start a few days ahead of your target date, keep every dose per its product label, and don't skip the photographs — spring-you reassembles from them.

  1. Balance the water a few days ahead

    Start midweek for a weekend close: bring alkalinity and pH into their label ranges and let the water settle. What you seal under the cover is what the pool soaks in until spring.

  2. Deep-clean the pool

    Brush, skim, and vacuum like company's coming. A pool that goes under the cover spotless comes out needing a rinse; one that goes under dirty comes out needing a project.

  3. Service the filter one last time

    Clean media goes into storage, dirty media comes out worse: backwash the sand or DE, rinse the cartridges, all per the manual, before anything drains.

  4. Apply winter chemicals per label

    Winter chemicals go in before shutdown, not after: label-dosed, circulated for a few hours, distributed evenly. A floater dropped on still water protects one corner.

  5. Lower the water level

    Your cover's manual sets the number — commonly a few inches under the skimmer for solid covers, barely below normal for mesh. Stop there. The remaining water isn't laziness; it's ballast holding the shell in the ground.

  6. Blow out the lines and plug returns

    Air through every line — skimmer, returns, cleaner — until each blows dry mist, plugging returns while the air still pushes. Nothing else on this list protects as much plumbing per minute.

  7. Protect the skimmer

    The skimmer throat is where trapped water has no escape — park a guard bottle or rated plug in it and let ice crush the cheap part.

  8. Add pool antifreeze where blowouts fall short

    Doubt is the criterion: any run you can't confirm dry gets pool-grade antifreeze at the label's per-foot rate. The automotive jug from the garage is for cars — it has no business in pool plumbing.

  9. Drain the equipment

    Nothing on the pad should hold water overnight: pull the drain plugs from pump, filter, heater, and feeder, stash them all in the pump basket, and carry the portable pieces indoors.

  10. Set the air pillow and cover

    Float a centered air pillow, then land the cover and secure it the way its design intends — bags, cable, or straps. Ice sheets need somewhere to collapse inward, and the pillow is that somewhere.

  11. Store chemicals properly

    Seal opened containers, keep oxidizers and acids separated, and store everything cool, dry, and locked away from kids and pets — exactly as each label describes.

  12. Remove and store ladders and rails

    Pull ladders, rails, and the diving-board hardware; rinse, dry, and store them out of the weather. Anchor sockets get a dab of protectant so spring bolts turn freely.

What to buy before the rush

The November crowd empties shelves in a predictable order. This is the short list worth owning before Arlington's window opens — nothing exotic, just the stuff everyone needs the same weekend.

  • Winter closing kit

    Season-length winter chemicals in one label-dosed box.

  • Air pillow

    Centers under the cover so ice pushes inward, not outward.

  • Winter cover

    Sized to overlap; the cheapest insurance the pool wears all winter.

  • Cover pump

    Keeps rain and melt off a solid cover all season.

  • Expansion plugs + skimmer guard

    The blowout's finishing move — one per return, one for the skimmer.

  • Pool antifreeze

    Backup for unverifiable lines; label rate per foot of pipe.

How Arlington compares locally

Arlington closes in the later half of Texas's calendar. Neighbors run close: Grand Prairie (6 mi away) models its deadline at November 6 (about a week earlier vs Arlington's November 12), while Mansfield (9 mi) shows November 12. The spring mirror of this page is the Arlington opening guide, and the season overview draws both windows on a single bar.

Local means local: Arlington's dates come from Arlington Municipal Airport, the nearest station with complete daily temperature normals — 3.1 miles southeast, about 630 feet up. Between that station and a Tarrant County backyard there's always a degree or two of microclimate; the windows are built wide enough to carry it.

Field notes for Arlington owners

Blowout first, antifreeze second

Air is the only guaranteed freeze protection: a line that's verifiably dry cannot burst. Antifreeze (pool-grade, per label) is the fallback for lines you can't confirm — long runs, low spots, water-feature plumbing. Doing antifreeze instead of a blowout, rather than in addition, is how most cracked returns happen.

The mesh-cover spring surprise, prevented in fall

Mesh-covered pools green up early because late-winter sun plus nutrient-carrying meltwater reaches the water. The fall counter-moves: close late and cold, dose the winter kit exactly per label, and plan an early-spring peek under the cover rather than a Memorial Day reveal.

What comes indoors

Cartridges, the cover pump when idle, chemical containers, and anything with a small motor overwinter better in the garage. Cold cycling is hard on plastics and seals; shelf space is cheaper than replacements. Label a single bin now and spring assembly becomes a scavenger hunt with a map.

Arlington pool closing FAQ

What temperature should water be to close a pool?

Close once water holds below about 65°F — the point where algae go mostly dormant — and before hard freezes. In Arlington, the 7-day mean drops through the threshold around November 2, so the window between then and November 12 is the sweet spot for a clean, stable close.

Can you close a pool too early?

Absolutely. A pool closed warm is an algae incubator: no circulation, fading sanitizer, and weeks of growth-friendly temperatures. Arlington's water doesn't settle below the risk zone until around November 2 — closing much before that trades a few weekends of maintenance for a rough spring.

Do I need antifreeze in pool lines?

Treat antifreeze as a backup, not a substitute: the real protection is air in dry lines. Where a full blowout isn't possible, pool-grade antifreeze per label is cheap insurance against a cracked pipe — worth it anywhere freezes are routine, and Arlington sees them from about November 21.

How far should I drain my pool for winter?

Less than most people think. Below the skimmer opening is the classic solid-cover target; mesh covers often specify higher water. The cover's own manual wins every argument, and "drain it completely" is never the answer — empty shells pop out of wet ground.

What happens if you don't winterize a pool?

The repair list writes itself in order of cost: heater heat exchanger, pump housing, filter tank, then every fitting the ice reached — discovered one leak at a time in spring. Around Arlington the exposure begins near November 21, and each skipped checklist step above is one more candidate for that list.

When is the last safe date to close in Arlington?

Our model's practical deadline is November 12 — set by the cool-down plus ten days (the freeze normal, November 21, leaves room to spare). Push much past it and you're winterizing in freeze-warning weather, rushing the blowout, and hoping the cover goes on before the first hard night. Inside the November 2–November 12 window, none of that drama applies.

Data: NOAA 1991–2020 climate normals via Arlington Municipal Airport (3.1 mi); live outlook by Open-Meteo. Full attribution on the sources page. Model assumptions and error bars on methodology.