Pool season · California
Simi Valley Pool Season: the Year on One Bar
Last updated: July 15, 2026 · dates · water temp
This is the one-page view of Simi Valley'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 Simi Valley's whole pool year into one lane rope: gray floats for the off-season, hollow teal for the March 5–March 26 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 Simi Valley pool calendar
Opening — target March 12
Target March 12; the practical window runs March 5–March 26, and the 7-day mean crosses the 61°F threshold around March 26. Cold-water starts are the cheap ones.
Closing — deadline November 26
Hold the cover until November 16, then winterize by November 26, a week ahead of the December 15 freeze normal. Late and cold beats early and warm.
Estimated water temperature by month
This is Simi Valley'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° | 56° | 58° | 62° | 65° | 70° | 76° | 79° | 78° | 73° | 65° | 57° |
Warmest water typically August–September (peaking near 79°F); heaters and covers shift any month up.
Email me when Simi Valley hits the closing window
Data: NOAA 1991–2020 climate normals via Woodland Hills Pierce College (11.6 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.