Arizona Pool Season: Opening & Closing Dates by City

Local dates for every featured Arizona city — when the water warms up, when it cools off, and how long the season actually lasts.

City Opening window Closing window Season
Phoenix Feb 24 – Mar 23 Nov 8 – Nov 25 ≈ 251 days
Tucson Mar 11 – Apr 9 Oct 29 – Nov 15 ≈ 226 days
Flagstaff Jun 21 – Jul 7 Aug 14 – Aug 29 ≈ 38 days

Windows show the stretch when each city's daily average passes through the low-to-mid 60s°F (1991–2020 NOAA records, nearest station to each city). Click a city for its month-by-month table and full season notes.

Season geography

Across Arizona's featured cities, typical openings spread from Mar 10 to Jul 7, closings from Aug 14 to Nov 15, and the unheated season runs 38–251 days depending on where you are. Elevation, coastal water, and urban heat all pull real dates around, which is exactly why a state-level answer isn't enough.

For your exact town, the pool season lookup takes a ZIP code. Opening day itself is a chemistry job — the dosing calculator turns your first test reading of the year into exact amounts.

Arizona planning pages

When to open — Arizona When to close — Arizona All states →