Pool season · Arizona
Tempe Pool Season: the Year on One Bar
Last updated: July 15, 2026 · dates · water temp
One bar, one year, one Tempe 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.
Each dot on the bar is one week of Tempe's typical year, colored by what the model says that week is for: gray weeks are off-season, hollow teal marks the opening window (February 13–March 6), solid teal is swim season, and hollow amber is the closing window ending November 28. The black marker is today — its position against the colors is the entire executive summary.
The Tempe pool calendar
Opening — target February 20
Target February 20; the practical window runs February 13–March 6, and the 7-day mean crosses the 61°F threshold around March 6. Cold-water starts are the cheap ones.
Closing — deadline November 28
The window opens November 18 once water leaves the algae zone; the model deadline is November 28, a week ahead of the December 5 freeze normal.
Estimated water temperature by month
This is Tempe'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.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 54° | 56° | 60° | 66° | 73° | 82° | 89° | 91° | 88° | 79° | 68° | 57° |
Warmest water typically June–October (peaking near 91°F); heaters and covers shift any month up.
Email me when Tempe hits the closing window
Data: NOAA 1991–2020 climate normals via Tempe ASU (2.7 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.