PoolWindow

Pool season · Arizona

Tucson Pool Season: the Year on One Bar

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

Tucson's whole pool calendar, condensed: when the water warms, when it cools, and where today falls between those edges. Use the opening guide and closing guide for the step-by-step work; keep this page for the dates.

Palm-lined pool deck in a warm year-round swim climateTucson, AZ — 218 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

Reading it takes ten seconds: 52 dots, one per week. Solid teal is Tucson's swim season; the hollow teal run before it (February 19 to March 12) is when to open; the hollow amber run after is when to close, with November 26 as the deadline; gray is the covered season. Today's marker shows where you stand in that cycle right now.

The Tucson pool calendar

February 26open by
November 26close by
21880°F+ days
88°Fwater peak

Opening — target February 26

Target February 26; the practical window runs February 19–March 12, and the 7-day mean crosses the 61°F threshold around March 12. Cold-water starts are the cheap ones.

Full opening guide

Closing — deadline November 26

Hold the cover until November 16, then winterize by November 26, a week ahead of the December 9 freeze normal. Late and cold beats early and warm.

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 Tucson water runs about 52°F at its winter floor and 88°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 Tucson'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.

40°50°60°70°80°90°100°JanFebMarAprMayJunJulAugSepOctNovDec65° algae zone58° swimmable startopen Feb 26close Nov 2688°F peak52°F floor
Site-model seasonal water estimates for an unheated in-ground pool near Tucson International Airport — ±5°F, see methodology.
JanFebMarAprMayJunJulAugSepOctNovDec
53°55°59°65°72°83°88°87°86°78°67°56°

Warmest water typically June–October (peaking near 88°F); heaters and covers shift any month up.

Every station tells its own story: compare this curve with Tempe's pool season and Yuma's — neighboring normals stations can shift the windows by a week or more. The full ranking lives on the Arizona season index.

Tucson pool season FAQ

When should I open my pool in Tucson, AZ?

Target February 26. That date backs off two weeks from the day Tucson's 7-day mean temperature reaches 61°F, so you start up in cold, algae-resistant water. Work the full checklist in the Tucson opening guide.

When should I close my pool in Tucson?

The closing deadline is November 26 — late enough that the water has cooled out of the algae zone, early enough to beat Tucson's first-freeze normal by about a week. See the Tucson closing guide for the winterizing steps.

How long is the swim season in Tucson?

Tucson averages 218 days a year with normal highs of 80°F or better — right on the statewide median. The Arizona season index ranks all 20 covered cities by the same metric.

How warm does pool water get in Tucson?

An unheated pool near Tucson typically peaks around 88°F in high summer and bottoms out near 52°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 Tucson International Airport (4.7 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.