Pool season · California
Palo Alto Pool Season: the Year on One Bar
Last updated: July 15, 2026 · dates · water temp
Palo Alto'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.
Reading it takes ten seconds: 52 dots, one per week. Solid teal is Palo Alto's swim season; the hollow teal run before it (April 23 to May 14) is when to open; the hollow amber run after is when to close, with October 27 as the deadline; gray is the covered season. Today's marker shows where you stand in that cycle right now.
The Palo Alto pool calendar
Opening — target April 30
Target April 30; the practical window runs April 23–May 14, and the 7-day mean crosses the 61°F threshold around May 14. Cold-water starts are the cheap ones.
Closing — deadline October 27
The window opens October 17 once water leaves the algae zone; the model deadline is October 27, a week ahead of the December 7 freeze normal.
Estimated water temperature by month
This is Palo Alto'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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 48° | 50° | 53° | 56° | 60° | 64° | 67° | 67° | 67° | 64° | 57° | 50° |
The curve peaks near 68°F — comfortable-water months here usually involve a heater or a solar cover.
Email me when Palo Alto hits the closing window
Data: NOAA 1991–2020 climate normals via Palo Alto (3.7 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.