PoolWindow

Pool season · Hawaii

Kailua Pool Season: the Year on One Bar

Last updated: July 25, 2026 · dates · water temp

No opening date, no closing deadline: Kailua's season bar below is one long swim window with a comfort gradient. The spring refresh and winter care pages hold the practical checklists for a pool that never sleeps; this page is the dashboard that says which of them applies today.

Palm-lined pool deck in a warm year-round swim climateKailua, HI — 231 swim days a year
J F M A M J J A S O N D today (build date)

off-season opening window swim season closing window

One color, 52 dots: Kailua's bar has no gray because the model never finds a week that forces a closing. Use the monthly water estimates below instead — the swing from 71°F to 80°F is what actually shapes swimming and maintenance here, from heater decisions at the cool end to sanitizer demand across the 231 days of genuine summer.

The Kailua pool calendar

Year-roundseason type
23180°F+ days
71°Fwater floor
80°Fwater peak

Spring refresh

The model finds no closing week in Kailua — maintenance is continuous, with a 231-day prime stretch of 80°F+ afternoons.

Open the refresh guide

Winter care

No forced dates: the 7-day mean never leaves the swim-viable range (floor 71.4°F). Spring refresh and winter care replace opening and closing.

Open the winter guide

Where the water sits today

SEASONAL VIEW

Estimated unheated pool water temp (site model, ±5°F). The live estimate loads in your browser from Open-Meteo air temperatures; in a typical year Kailua water runs about 71°F at its winter floor and 80°F at its summer peak.

40 45 50 55 60 65 70 75 80 85 58 open 65 algae

Estimated water temperature by month

Monthly averages of the site's water model run on Kailua's own normals — the shape of a typical year, not a forecast. The widget above shows where the current year actually sits.

60°70°80°90°JanFebMarAprMayJunJulAugSepOctNovDec65° algae zone80°F peak71°F floor
Site-model seasonal water estimates for an unheated in-ground pool near Waimanalo Experiment F 795.1 — ±5°F, see methodology.
JanFebMarAprMayJunJulAugSepOctNovDec
72°72°72°74°75°77°79°79°80°79°77°75°

Warmest water typically July–October (peaking near 80°F); heaters and covers shift any month up.

Every station tells its own story: compare this curve with Honolulu's pool season or jump back to the Hawaii season index to see the statewide spread.

Kailua pool season FAQ

Does Kailua, HI need a seasonal pool opening?

No — the model classifies Kailua as a year-round climate: the 7-day mean temperature never settles below the 61°F threshold long enough to justify a hard winter shutdown. Keep the pump circulating and the sanitizer in range through the cool months instead. Details are in the Kailua opening guide.

Should you ever close a pool in Kailua?

Rarely. With 231 days of 80°F+ highs a year, most Kailua owners run the pool continuously and simply trim pump hours in the cool season. If you do want a shutdown checklist, the Kailua closing guide covers the mild-winter variant.

How long is the swim season in Kailua?

Kailua averages 231 days a year with normal highs of 80°F or better. The Hawaii season index ranks all 2 covered cities by the same metric.

How warm does pool water get in Kailua?

An unheated pool near Kailua typically peaks around 80°F in high summer and bottoms out near 71°F in winter, spending roughly 4 months at or above the 78°F comfort line most swimmers prefer. The month-by-month curve above shows the whole cycle; the methodology page explains the ±5°F error bars.

Data: NOAA 1991–2020 climate normals via Waimanalo Experiment F 795.1 (4.3 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.