Pool closing · South Carolina
When to Close Your Pool in Florence, SC: Deadline, Window & Checklist
Last updated: July 15, 2026 · Model window year: 2026 · dates · checklist · FAQ
Plan to close your Florence pool by November 6. The local 7-day mean temperature drops out of the algae-risk zone around October 28, and NOAA normals put the first 32°F freeze near November 13 — winterize between those dates and the water goes under the cover cold, clean, and easy to reopen. Below: today's water estimate, the full closing window, and a step-by-step winterizing checklist.
Florence closing dates at a glance
| Closing window | October 28 – November 6 |
|---|---|
| Close by (deadline) | November 6 |
| First freeze, 50% probability | November 13 |
| Open by (recommended) | March 21 |
| Opening window | March 14 – April 4 |
| 61°F crossing (7-day mean) | April 4 |
| Swim-season length (80°F+ days) | 160 days |
| NOAA normals station | Florence Regional Airport · 3.8 mi · 146 ft |
A classic four-season pool calendar: open early into cold water, close late into cold water, and Florence's 160 days of prime swimming sit safely in between.
The same model in water terms: Florence's estimated pool temperature runs about 63°F in mid-April, 78°F in mid-June, 81°F in mid-August, and 68°F in mid-October, peaking near 82°F. Those four checkpoints — not any calendar holiday — are what the windows above are protecting.
The 12-step Florence winterizing checklist
Sequenced against Florence's October 28–November 6 window: chemistry while the pump still runs, blowouts before the equipment drains, cover last. Labels dictate every dose.
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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.
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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
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.
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Apply winter chemicals per label
Dose the winter kit while the pump still runs — every product exactly per its label for your volume — so the chemistry is fully mixed before the system goes quiet.
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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.
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Blow out the lines and plug returns
The blowout is the whole ballgame: drive air through each line until it runs dry, seat the plug against the airflow, move to the next. A dry line cannot burst, full stop.
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Protect the skimmer
Give the skimmer something cheap to break: a guard bottle or rated plug absorbs the ice expansion that would otherwise split the housing.
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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.
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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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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.
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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 Florence's October rush and the whole list ships at leisure instead of sprinting.
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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
Pool-rated glycol for the lines air couldn't clear.
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Winter closing kit
Season-length winter chemicals in one label-dosed box.
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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
Keeps rain and melt off a solid cover all season.
How Florence compares locally
Florence closes in the earliest quarter of South Carolina's calendar. Neighbors run close: Sumter (38 mi away) models its deadline at October 30 (about a week earlier vs Florence's November 6), while Myrtle Beach (61 mi) shows November 5. The spring mirror of this page is the Florence opening guide, and the season overview draws both windows on a single bar.
Every number on this page traces to one instrument cluster: Florence Regional Airport, 3.8 miles east of Florence's center at an elevation near 146 feet. NOAA computed its 1991–2020 normals from roughly three decades of daily readings — long enough that one strange spring in Florence County barely moves the dates.
Field notes for Florence owners
Salt cells overwinter indoors
Remove the cell at closing, inspect and clean per the manufacturer, and store it inside with the unions capped. A dummy cell or spacer keeps the plumbing sealed. Cells left in outdoor plumbing through freezes are a common — and completely avoidable — spring casualty.
Gas heaters get the manual, not a guess
Every heater brand sequences its winterizing differently — drain plugs, blower considerations, gas supply, control settings. The generic advice (drain fully, close the valve) is right but incomplete; ten minutes with your model's manual protects the most expensive component you'll winterize.
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.
Florence 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. Florence's cool-down lands near October 28 in the normals, which is why the window opens there.
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. Florence's water doesn't settle below the risk zone until around October 28 — 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 Florence sees them from about November 13.
How far should I drain my pool for winter?
As far as your cover manufacturer specifies and no farther — typically a few inches below the skimmer mouth for solid covers, near normal level for many mesh systems with skimmer plugs. Never drain fully: an empty shell can shift or crack under groundwater pressure.
What happens if you don't winterize a pool?
Expect equipment damage first — cracked pump volutes, split filter tanks, ruptured heater exchangers — then plumbing leaks that surface at startup. In Florence, normals put the first freeze near November 13; everything after that date is borrowed time for an unwinterized system.
When is the last safe date to close in Florence?
Our model's practical deadline is November 6 — set by a week of margin before the November 13 first-freeze normal. 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 October 28–November 6 window, none of that drama applies.
Email me when Florence hits the closing window
Data: NOAA 1991–2020 climate normals via Florence Regional Airport (3.8 mi); live outlook by Open-Meteo. Full attribution on the sources page. Model assumptions and error bars on methodology.