Pool season · California
El Cajon Pool Season: the Year on One Bar
Last updated: July 15, 2026 · dates · water temp
El Cajon'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.
The bar compresses El Cajon's whole pool year into one lane rope: gray floats for the off-season, hollow teal for the March 9–March 30 opening window, solid teal for swim weeks, hollow amber for the closing stretch that ends November 26. Wherever the today marker sits, the nearest color change is your next appointment.
The El Cajon pool calendar
Opening — target March 16
Open by March 16 — a two-week head start on the March 30 crossing keeps startup chemistry small and beats the local service rush.
Closing — deadline November 26
The window opens November 16 once water leaves the algae zone; the model deadline is November 26, a week ahead of the December 21 freeze normal.
Estimated water temperature by month
This is El Cajon'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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 55° | 56° | 58° | 61° | 64° | 68° | 73° | 76° | 76° | 71° | 65° | 57° |
The curve peaks near 77°F — comfortable-water months here usually involve a heater or a solar cover.
Email me when El Cajon hits the closing window
Data: NOAA 1991–2020 climate normals via El Cajon (1.9 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.