Pool closing · Indiana
When to Close Your Pool in Evansville, IN: Deadline, Window & Checklist
Last updated: July 15, 2026 · Model window year: 2026 · dates · checklist · FAQ
Circle October 27 on the Evansville calendar. Closing earlier traps warm, algae-friendly water under the cover; closing later gambles the plumbing against the first freeze, which the 1991–2020 normals place near November 10. The window opens October 17 — the live widget below shows how this year is actually tracking against it.
Evansville closing dates at a glance
| Closing window | October 17 – October 27 |
|---|---|
| Close by (deadline) | October 27 |
| First freeze, 50% probability | November 10 |
| Open by (recommended) | April 6 |
| Opening window | March 30 – April 20 |
| 61°F crossing (7-day mean) | April 20 |
| Swim-season length (80°F+ days) | 127 days |
| NOAA normals station | Evansville Museum · 2.7 mi · 374 ft |
Evansville's 127-day warm season leaves comfortable margins on both ends — the windows above aim you at the cheap-chemistry versions of each transition.
Four water checkpoints anchor Evansville's year in the model: mid-April at about 58°F, mid-June at 75°F, mid-August near the 80°F peak zone, and mid-October easing through 64°F. The dates in the table are where those numbers cross the thresholds that matter.
The 12-step Evansville winterizing checklist
The order matters more than the date: balanced water first, verified-dry lines before anything else freezes-proofs, and the cover only after everything below it is done. Work the list inside the window above.
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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
Leave nothing organic behind: skim the surface, brush every wall and step, vacuum the floor slowly. What goes under the cover dirty comes out worse — winter only ever compounds what it's given.
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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.
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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
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
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
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.
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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
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.
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Winterize the water features
Waterfalls, slides, and spillover spas hold water in places gravity won't clear — blow those lines separately and plug them, or they'll be the one crack you find in spring.
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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.
What to buy before the rush
The October crowd empties shelves in a predictable order. This is the short list worth owning before Evansville's window opens — nothing exotic, just the stuff everyone needs the same weekend.
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Pool antifreeze
For lines you can't verify dry — pool-grade only, per label.
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Winter closing kit
Closing chemistry in one box, dosed by pool volume.
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Air pillow
A soft target for the ice sheet, centered under the cover.
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Winter cover
Sized to overlap; the cheapest insurance the pool wears all winter.
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Cover pump
Standing water is a cover killer; this is the counter.
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Expansion plugs + skimmer guard
Seals blown-out lines and sacrifices itself to skimmer ice.
How Evansville compares locally
Statewide context: across the 13 Indiana cities we model, Evansville's October 27 deadline sits in the earliest quarter. Nearby, Bowling Green (92 mi) closes around October 23 and Elizabethtown (93 mi) around October 14 — treat gaps under a week as microclimate noise, not strategy. Spring planning restarts at the opening guide; the Evansville pool season page keeps the whole year in one view.
Every number on this page traces to one instrument cluster: Evansville Museum, 2.7 miles southwest of Evansville's center at an elevation near 374 feet. NOAA computed its 1991–2020 normals from roughly three decades of daily readings — long enough that one strange spring in Vanderburgh County barely moves the dates.
Field notes for Evansville owners
The warm spell after you closed
A 78°F week in October doesn't mean reopening. Water under an opaque cover warms far less than air suggests, and a closed, balanced pool tolerates a warm stretch fine. Check the cover pump has somewhere to send rain, enjoy the weather, and leave the plumbing sealed.
The skimmer is the most breakable part you own
Skimmer bodies crack because water freezes inside the throat with nowhere to push. A sacrificial bottle or spring-loaded guard absorbs that expansion for a few dollars. It's the highest-return item in the entire closing kit relative to what it protects.
The fifteen-minute monthly walk-around
Once a month all winter: pump or siphon standing water off solid covers, re-tension straps or top up water bags, confirm the level hasn't dropped enough to strand the cover, and glance at the pad for critter nests. Every major cover failure starts as a skipped walk-around.
Evansville 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. Evansville's cool-down lands near October 17 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 Evansville's water cool through the mid-60s°F — around October 17 by our model — then close inside the window that ends October 27.
Do I need antifreeze in pool lines?
Only where water might remain. If every line is properly blown out and plugged, air is the antifreeze. Lines you can't verify dry — long runs, low spots, water features — get pool-grade antifreeze dosed per its label. With Evansville's first freeze normal near November 10, don't leave that question open.
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?
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. Evansville reaches freeze territory around November 10 — the checklist above is cheaper than any one of those repairs.
When is the last safe date to close in Evansville?
The model draws the line at October 27 for Evansville. It isn't arbitrary: the cool-down plus ten days (the freeze normal, November 10, leaves room to spare), and the whole closing sequence needs a working weekend of margin. The one exception that overrides any date — a hard freeze inside the 10-day forecast, which the widget above flags as urgent.
Email me when Evansville hits the closing window
Data: NOAA 1991–2020 climate normals via Evansville Museum (2.7 mi); live outlook by Open-Meteo. Full attribution on the sources page. Model assumptions and error bars on methodology.