PoolWindow

Pool season · Arizona

Maricopa Pool Season: the Year on One Bar

Last updated: July 15, 2026 · dates · water temp

One bar, one year, one Maricopa pool. The season bar below draws everything the model knows — opening window, prime season, closing window — against today's date, with the working details one click away on the opening and closing pages.

J F M A M J J A S O N D today (build date)

off-season opening window swim season closing window

The bar compresses Maricopa's whole pool year into one lane rope: gray floats for the off-season, hollow teal for the February 18–March 11 opening window, solid teal for swim weeks, hollow amber for the closing stretch that ends November 17. Wherever the today marker sits, the nearest color change is your next appointment.

The Maricopa pool calendar

February 25open by
November 17close by
24180°F+ days
94°Fwater peak

Opening — target February 25

Open by February 25 — a two-week head start on the March 11 crossing keeps startup chemistry small and beats the local service rush.

Full opening guide

Closing — deadline November 17

The window opens November 14 once water leaves the algae zone; the model deadline is November 17, a week ahead of the November 24 freeze normal.

Full closing 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 Maricopa water runs about 51°F at its winter floor and 94°F at its summer peak.

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

Estimated water temperature by month

This is Maricopa's typical-year water curve: the same EWMA model as the live widget, run on the 1991–2020 normals instead of this week's weather.

Site-model seasonal water estimates for an unheated in-ground pool near Maricopa 4 N — ±5°F, see methodology.
JanFebMarAprMayJunJulAugSepOctNovDec
52°55°59°66°74°84°92°93°90°79°66°55°

Warmest water typically June–October (peaking near 94°F); heaters and covers shift any month up.

Data: NOAA 1991–2020 climate normals via Maricopa 4 N (5.3 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.