Pool season · California
Vacaville Pool Season: the Year on One Bar
Last updated: July 15, 2026 · dates · water temp
This is the one-page view of Vacaville'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.
Reading it takes ten seconds: 52 dots, one per week. Solid teal is Vacaville's swim season; the hollow teal run before it (April 4 to April 25) is when to open; the hollow amber run after is when to close, with November 5 as the deadline; gray is the covered season. Today's marker shows where you stand in that cycle right now.
The Vacaville pool calendar
Opening — target April 11
Target April 11; the practical window runs April 4–April 25, and the 7-day mean crosses the 61°F threshold around April 25. Cold-water starts are the cheap ones.
Closing — deadline November 5
Hold the cover until October 26, then winterize by November 5, a week ahead of the November 28 freeze normal. Late and cold beats early and warm.
Estimated water temperature by month
This is Vacaville'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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 47° | 49° | 54° | 57° | 63° | 70° | 76° | 76° | 75° | 69° | 59° | 50° |
The curve peaks near 77°F — comfortable-water months here usually involve a heater or a solar cover.
Email me when Vacaville hits the closing window
Data: NOAA 1991–2020 climate normals via Vacaville Nut Tree Airport (1.4 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.