Pool season · California
San Diego Pool Season: the Year on One Bar
Last updated: July 15, 2026 · dates · water temp
One bar, one year, one San Diego 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 San Diego's typical year, colored by what the model says that week is for: gray weeks are off-season, hollow teal marks the opening window (March 21–April 11), solid teal is swim season, and hollow amber is the closing window ending November 27. The black marker is today — its position against the colors is the entire executive summary.
The San Diego pool calendar
Opening — target March 28
Target March 28; the practical window runs March 21–April 11, and the 7-day mean crosses the 61°F threshold around April 11. Cold-water starts are the cheap ones.
Closing — deadline November 27
Hold the cover until November 17, then winterize by November 27, a week ahead of the December 21 freeze normal. Late and cold beats early and warm.
Estimated water temperature by month
This is San Diego'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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 56° | 57° | 58° | 60° | 63° | 66° | 70° | 73° | 74° | 70° | 65° | 58° |
The curve peaks near 74°F — comfortable-water months here usually involve a heater or a solar cover.
Email me when San Diego hits the closing window
Data: NOAA 1991–2020 climate normals via San Diego Montgomery Field (1.5 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.