Pool season · California
Walnut Creek Pool Season: the Year on One Bar
Last updated: July 15, 2026 · dates · water temp
This is the one-page view of Walnut Creek's pool year: both model windows, the estimated water-temperature curve, and today's live position on the season bar. The detailed checklists live on the opening and closing guides; this page is the calendar you check between them.
The bar compresses Walnut Creek's whole pool year into one lane rope: gray floats for the off-season, hollow teal for the March 28–April 18 opening window, solid teal for swim weeks, hollow amber for the closing stretch that ends November 11. Wherever the today marker sits, the nearest color change is your next appointment.
The Walnut Creek pool calendar
Opening — target April 4
Open by April 4 — a two-week head start on the April 18 crossing keeps startup chemistry small and beats the local service rush.
Closing — deadline November 11
The window opens November 1 once water leaves the algae zone; the model deadline is November 11, a week ahead of the December 19 freeze normal.
Estimated water temperature by month
This is Walnut Creek'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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 50° | 52° | 56° | 59° | 63° | 68° | 73° | 73° | 73° | 69° | 61° | 52° |
The curve peaks near 74°F — comfortable-water months here usually involve a heater or a solar cover.
Email me when Walnut Creek hits the closing window
Data: NOAA 1991–2020 climate normals via Concord Wwtp (5.8 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.