Pool closing · Texas
When to Close Your Pool in McKinney, TX: Deadline, Window & Checklist
Last updated: July 15, 2026 · Model window year: 2026 · dates · checklist · FAQ
Target November 8 as the practical closing deadline in McKinney. Our model of NOAA 1991–2020 normals keeps the 7-day mean above 61°F until October 30; after that, cooling water winds algae down while you work the checklist below. The hard stop is equipment freeze damage — normals put McKinney's first 32°F night near November 15.
McKinney closing dates at a glance
| Closing window | October 30 – November 8 |
|---|---|
| Close by (deadline) | November 8 |
| First freeze, 50% probability | November 15 |
| Open by (recommended) | March 17 |
| Opening window | March 10 – March 31 |
| 61°F crossing (7-day mean) | March 31 |
| Swim-season length (80°F+ days) | 161 days |
| NOAA normals station | Mckinney Municipal Airport · 4.4 mi · 586 ft |
McKinney's 161-day warm season leaves comfortable margins on both ends — the windows above aim you at the cheap-chemistry versions of each transition.
The same model in water terms: McKinney's estimated pool temperature runs about 63°F in mid-April, 79°F in mid-June, 84°F in mid-August, and 69°F in mid-October, peaking near 84°F. Those four checkpoints — not any calendar holiday — are what the windows above are protecting.
The 12-step McKinney 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.
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Balance the water a few days ahead
Give the chemistry a head start — balance to label ranges several days out, while circulation can still mix corrections evenly. Closing-day dosing never distributes as well.
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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.
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Service the filter one last time
Send the filter into winter clean: backwash the sand or DE, rinse and dry the cartridges indoors. Media stored dirty over winter hardens into a spring problem no backwash fixes.
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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.
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Lower the water level
Drop the level as your cover manufacturer specifies — typically below the skimmer mouth for solid covers. Never drain a pool fully; groundwater pressure can damage the shell.
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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.
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Protect the skimmer
Seat a skimmer guard or bottle in the throat — ice that forms there needs a sacrifice, and a two-dollar bottle beats a plumbing repair under the deck.
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Add pool antifreeze where blowouts fall short
If any line can't be verified dry, add pool-grade antifreeze per its label. Use only pool antifreeze — automotive products don't belong in pool plumbing.
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Drain the equipment
Open every drain plug on the pump, filter, heater, and chlorinator, and store the plugs in the pump basket so spring reassembly is a one-stop hunt. Move what you can indoors.
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Set the air pillow and cover
Pillow first, cover second, tension last. A properly centered pillow turns the winter ice sheet from a wall-pressing ram into a harmless dome.
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Calendar the off-season checks
Set a monthly reminder from November 8 to spring: check cover tension, pump off standing water, and glance at the water level. Fifteen minutes a month protects the whole closing job.
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Shut down the heater carefully
Follow the manufacturer's winterizing sequence for your heater — drain it fully and, for gas units, close the supply valve. Heat exchangers are the most expensive freeze casualty on the pad.
What to buy before the rush
The October crowd empties shelves in a predictable order. This is the short list worth owning before McKinney's window opens — nothing exotic, just the stuff everyone needs the same weekend.
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Winter closing kit
The under-the-cover chemistry, measured for your gallons.
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Air pillow
Gives ice somewhere to push besides your pool walls.
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Winter cover
Measure with overlap; the winter workhorse over everything else.
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Cover pump
Solid covers collect rain all winter; this is the drainage plan.
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Expansion plugs + skimmer guard
The blowout's finishing move — one per return, one for the skimmer.
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Pool antifreeze
Backup for unverifiable lines; label rate per foot of pipe.
How McKinney compares locally
McKinney closes in the latest quarter of Texas's calendar. Neighbors run close: Allen (6 mi away) models its deadline at November 4 (about a week earlier vs McKinney's November 8), while Frisco (9 mi) shows November 9. The spring mirror of this page is the McKinney opening guide, and the season overview draws both windows on a single bar.
The measuring stick here is Mckinney Municipal Airport — 4.4 miles to the east, elevation about 586 feet. Its 1991–2020 record is what the model reads for McKinney; your backyard in Collin County will run a touch warmer or cooler with shade, wind, and pavement, which is exactly the slack the two-week lead absorbs.
Field notes for McKinney owners
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.
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.
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.
McKinney pool closing FAQ
What temperature should water be to close a pool?
Below roughly 65°F, and trending down. Water closed warm keeps feeding algae under the cover for weeks; water closed in the 50s goes dormant almost immediately. McKinney's cool-down lands near October 30 in the normals, which is why the window opens there.
Can you close a pool too early?
You can, and warm-water closings are why "we opened to a swamp" stories exist. The fix is patience: let McKinney's water cool through the mid-60s°F — around October 30 by our model — then close inside the window that ends November 8.
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 McKinney the freeze clock starts around November 15, 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 freeze finds every shortcut. Ice in an unprotected pump or heater cracks castings from the inside; ice in underground lines splits fittings you can't see until spring. McKinney reaches freeze territory around November 15 — the checklist above is cheaper than any one of those repairs.
When is the last safe date to close in McKinney?
November 8, by our model — a week of margin before the November 15 first-freeze normal. Later closes happen, but they happen in gloves. The winterizing steps above take a weekend; leave yourself at least that much runway before McKinney's first freeze-risk stretch.
Email me when McKinney hits the closing window
Data: NOAA 1991–2020 climate normals via Mckinney Municipal Airport (4.4 mi); live outlook by Open-Meteo. Full attribution on the sources page. Model assumptions and error bars on methodology.