When to Close Your Pool in Los Angeles, CA: Deadline, Window & Checklist

Los Angeles closing dates at a glance

A short season cuts both ways: every week opened before April 5 is a real slice of Los Angeles's roughly 0-day warm-swim budget.

Four water checkpoints anchor Los Angeles's year in the model: mid-April at about 61°F, mid-June at 65°F, mid-August near the 71°F peak zone, and mid-October easing through 68°F. The dates in the table are where those numbers cross the thresholds that matter.

The 12-step Los Angeles 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.

1. Balance the water a few days ahead

   Do the chemistry midweek, close on the weekend: alkalinity and pH into label ranges with days of circulation left to spread them. Winter locks in whatever state the water holds on closing day.

2. 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.

3. 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.

4. 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.

5. Lower the water level

   Take the level down only as far as the cover's manual says — usually just below the skimmer for solid covers, higher for many mesh systems. An empty pool is never the goal; shells crack and shift without water's weight.

6. 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.

7. 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.

8. 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.

9. 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.

10. 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.

11. 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.

12. Note this year's dates

    Jot down when Los Angeles's water actually cooled and when you closed. A two-line note beats memory next November 28 — your own yard runs a few days off any model, including ours.

What to buy before the rush

Every item below sells out somewhere in California every November. Stocking the short list before the rush costs nothing extra and saves the mid-project store run — the chemicals guide explains what each category actually does.

• Cover pump

  Solid covers collect rain all winter; this is the drainage plan.

• Expansion plugs + skimmer guard

  Seals blown-out lines and sacrifices itself to skimmer ice.

• Pool antifreeze

  Backup for unverifiable lines; label rate per foot of pipe.

• Winter closing kit

  Closing chemistry in one box, dosed by pool volume.

• Air pillow

  A soft target for the ice sheet, centered under the cover.

• Winter cover

  Sized to overlap; the cheapest insurance the pool wears all winter.

How Los Angeles compares locally

Two nearby data points to triangulate with: Burbank, 7 miles from Los Angeles, models its close at November 23 (roughly two weeks earlier); Santa Monica, 8 miles out, at November 20. Los Angeles's own window ends December 8. For the other half of the calendar see when to open in Los Angeles, or scan the full year on the season page.

Local means local: Los Angeles's dates come from U C L A, the nearest station with complete daily temperature normals — 3.7 miles southwest, about 430 feet up. Between that station and a Los Angeles County backyard there's always a degree or two of microclimate; the windows are built wide enough to carry it.

Field notes for Los Angeles 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.

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.

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.

Hard-winter homework

Where winter is long — Los Angeles banks only about 0 warm-swim days — the closing carries months of load. Bury the effort where it counts: verified-dry lines, fully drained equipment, a skimmer guard, and a cover secured for real wind. A short season forgives a late opening; it never forgives a cracked pump.