Pool closing · Texas
When to Close Your Pool in Dallas, TX: Deadline, Window & Checklist
Last updated: July 15, 2026 · Model window year: 2026 · dates · checklist · FAQ
Target November 16 as the practical closing deadline in Dallas. Our model of NOAA 1991–2020 normals keeps the 7-day mean above 61°F until November 6; after that, cooling water winds algae down while you work the checklist below. The hard stop is equipment freeze damage — normals put Dallas's first 32°F night near November 29.
Dallas closing dates at a glance
| Closing window | November 6 – November 16 |
|---|---|
| Close by (deadline) | November 16 |
| First freeze, 50% probability | November 29 |
| Open by (recommended) | March 7 |
| Opening window | February 28 – March 21 |
| 61°F crossing (7-day mean) | March 21 |
| Swim-season length (80°F+ days) | 170 days |
| NOAA normals station | Dallas Love Field · 6.5 mi · 440 ft |
A classic four-season pool calendar: open early into cold water, close late into cold water, and Dallas's 170 days of prime swimming sit safely in between.
The same model in water terms: Dallas's estimated pool temperature runs about 66°F in mid-April, 82°F in mid-June, 88°F in mid-August, and 72°F in mid-October, peaking near 88°F. Those four checkpoints — not any calendar holiday — are what the windows above are protecting.
The 12-step Dallas 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.
-
Balance the water a few days ahead
Three or four days before closing, adjust alkalinity and pH into label ranges. Balanced water is gentler on the liner, plaster, and equipment through the long covered months ahead.
-
Deep-clean the pool
Skim, brush walls and steps, and vacuum carefully. Any leaves or algae you seal under the cover become spring's chemistry problem, so closing day cleanliness pays twice.
-
Service the filter one last time
One final filter service per the manual — cartridges rinsed and stored dry indoors, sand or DE backwashed. Winter turns trapped gunk into concrete.
-
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.
-
Lower the water level
Check the cover manufacturer's spec before touching the hose: solid covers typically want water below the skimmer mouth, mesh often barely lower than normal. Full draining is off the table entirely.
-
Blow out the lines and plug returns
Push air through skimmer, return, and cleaner lines until they run dry mist, then seat expansion plugs at each return while air still flows. This is the single most important freeze-protection step.
-
Protect the skimmer
Install a skimmer guard bottle (or a plug rated for your skimmer) so ice that forms there crushes the sacrificial piece instead of cracking the skimmer body.
-
Add pool antifreeze where blowouts fall short
Any line you can't prove is dry gets pool-grade antifreeze at the label's rate per foot. Automotive antifreeze is toxic in this context — pool-rated only, always.
-
Drain the equipment
Open the drains on everything that holds water and let the pad empty completely. Cartridges and small equipment overwinter far better on a garage shelf than outside.
-
Set the air pillow and cover
Center an inflated air pillow, then fit the cover and secure it with water bags, cable, or straps as designed. The pillow gives ice a place to push besides your walls.
-
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.
-
Stage the cover pump
Solid covers need drainage all winter: set a cover pump or siphon before the first storm, not after. Standing water strains seams and invites a mid-winter emergency.
What to buy before the rush
A small stack of supplies turns the checklist above into a single-weekend job. Buy before Dallas's November rush and the whole list ships at leisure instead of sprinting.
-
Winter cover
Measure with overlap; the winter workhorse over everything else.
-
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.
-
Winter closing kit
The under-the-cover chemistry, measured for your gallons.
-
Air pillow
Gives ice somewhere to push besides your pool walls.
How Dallas compares locally
Dallas closes in the earlier half of Texas's calendar. Neighbors run close: Mesquite (11 mi away) models its deadline at November 10 (about a week earlier vs Dallas's November 16), while Garland (11 mi) shows November 9. The spring mirror of this page is the Dallas opening guide, and the season overview draws both windows on a single bar.
Local means local: Dallas's dates come from Dallas Love Field, the nearest station with complete daily temperature normals — 6.5 miles northwest, about 440 feet up. Between that station and a Dallas County backyard there's always a degree or two of microclimate; the windows are built wide enough to carry it.
Field notes for Dallas owners
Cold water is the whole point
A pool closed at 55°F barely changes all winter: algae are dormant, chemicals hold, and spring opens with a light dusting instead of a bloom. A pool closed at 72°F runs its own quiet ecosystem under the cover for a month. The date matters less than the water temperature it represents.
Match the drainage plan to the cover
Solid covers shed nothing — they need a cover pump staged before the first storm and checked after each one. Mesh covers drain themselves but pass silt that settles all winter. Either way, the plan is decided in October, not improvised in January when the cover is an ice sheet.
Leaf season vs closing day
If your yard drops serious leaves, the cheap trick is a leaf net over the main cover through the drop, then one bulk removal before snow. Leaves that winter on (or worse, under) the cover steep like tea and hand you stained water and clogged pumps in spring.
Dallas 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 Dallas, the 7-day mean drops through the threshold around November 6, so the window between then and November 16 is the sweet spot for a clean, stable close.
Can you close a pool too early?
Yes — it's the most common closing mistake. Seal 70°F water under a cover and algae keep growing in the dark all autumn; the spring opening turns green and expensive. In Dallas, hold off until the cool-down near November 6 before covering.
Do I need antifreeze in pool lines?
Blown-out, plugged lines don't need it; doubtful lines do. Use only antifreeze labeled for pools, at the label's rate per foot of pipe — never automotive antifreeze. In Dallas the freeze clock starts around November 29, so settle this during closing, not during the first cold snap.
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 Dallas the exposure begins near November 29, and each skipped checklist step above is one more candidate for that list.
When is the last safe date to close in Dallas?
Our model's practical deadline is November 16 — set by the cool-down plus ten days (the freeze normal, November 29, 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 6–November 16 window, none of that drama applies.
Email me when Dallas hits the closing window
Data: NOAA 1991–2020 climate normals via Dallas Love Field (6.5 mi); live outlook by Open-Meteo. Full attribution on the sources page. Model assumptions and error bars on methodology.