Pool closing · California
When to Close Your Pool in Davis, CA: Deadline, Window & Checklist
Last updated: July 15, 2026 · Model window year: 2026 · dates · checklist · FAQ
Two dates decide a Davis closing: October 26, when the 7-day mean drops back through 61°F and the water goes algae-quiet, and November 5, the model deadline set a safe week ahead of the December 1 first-freeze normal. Everything on this page — live water estimate, window, winterizing sequence — exists to land you between them.
Davis closing dates at a glance
| Closing window | October 26 – November 5 |
|---|---|
| Close by (deadline) | November 5 |
| First freeze, 50% probability | December 1 |
| Open by (recommended) | April 9 |
| Opening window | April 2 – April 23 |
| 61°F crossing (7-day mean) | April 23 |
| Swim-season length (80°F+ days) | 158 days |
| NOAA normals station | Davis 2 WSW Experiment Farm · 2.5 mi · 60 ft |
Davis's 158-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: Davis's estimated pool temperature runs about 58°F in mid-April, 71°F in mid-June, 75°F in mid-August, and 67°F in mid-October, peaking near 75°F. Those four checkpoints — not any calendar holiday — are what the windows above are protecting.
The 12-step Davis winterizing checklist
Sequenced against Davis's October 26–November 5 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
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
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
Add a winterizing kit or your usual closing chemicals exactly as their labels direct for your volume, with the pump still circulating so everything distributes before shutdown.
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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.
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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.
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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
Every vessel on the pad — pump, filter, heater, chlorinator — gets its drain plugs pulled. Drop all the plugs in the pump basket; that's the one place everyone looks first in spring.
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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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Calendar the off-season checks
Set a monthly reminder from November 5 to spring: check cover tension, pump off standing water, and glance at the water level. Fifteen minutes a month protects the whole closing job.
What to buy before the rush
A small stack of supplies turns the checklist above into a single-weekend job. Buy before Davis's October rush and the whole list ships at leisure instead of sprinting.
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Cover pump
Keeps rain and melt off a solid cover all season.
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Expansion plugs + skimmer guard
Seals blown-out lines and sacrifices itself to skimmer ice.
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Pool antifreeze
Pool-rated glycol for the lines air couldn't clear.
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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
The one purchase every other closing step depends on.
How Davis compares locally
Two nearby data points to triangulate with: Sacramento, 15 miles from Davis, models its close at November 9 (about a week later); Vacaville, 18 miles out, at November 5. Davis's own window ends November 5. For the other half of the calendar see when to open in Davis, or scan the full year on the season page.
Local means local: Davis's dates come from Davis 2 WSW Experiment Farm, the nearest station with complete daily temperature normals — 2.5 miles southwest, about 60 feet up. Between that station and a Yolo County backyard there's always a degree or two of microclimate; the windows are built wide enough to carry it.
Field notes for Davis owners
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.
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.
Davis pool closing FAQ
What temperature should water be to close a pool?
The practical target is water in the low 60s°F or below at closing day. Our Davis model has the sustained cool-down starting October 26; closing between then and November 5 means chemistry stays put and the spring reveal is a mild one.
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 Davis's water cool through the mid-60s°F — around October 26 by our model — then close inside the window that ends November 5.
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 Davis's first freeze normal near December 1, don't leave that question open.
How far should I drain my pool for winter?
Follow the cover's instructions first: solid covers usually want water a few inches below the skimmer; some mesh setups run higher with the skimmer sealed. The hard rule is never empty — hydrostatic pressure can lift or crack an empty pool, a far worse outcome than any freeze.
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 Davis the exposure begins near December 1, and each skipped checklist step above is one more candidate for that list.
When is the last safe date to close in Davis?
The model draws the line at November 5 for Davis. It isn't arbitrary: the cool-down plus ten days (the freeze normal, December 1, 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 Davis hits the closing window
Data: NOAA 1991–2020 climate normals via Davis 2 WSW Experiment Farm (2.5 mi); live outlook by Open-Meteo. Full attribution on the sources page. Model assumptions and error bars on methodology.