Pool season · California
Fremont Pool Season: the Year on One Bar
Last updated: July 15, 2026 · dates · water temp
This is the one-page view of Fremont'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 Fremont's swim season; the hollow teal run before it (April 21 to May 12) is when to open; the hollow amber run after is when to close, with November 2 as the deadline; gray is the covered season. Today's marker shows where you stand in that cycle right now.
The Fremont pool calendar
Opening — target April 28
Open by April 28 — a two-week head start on the May 12 crossing keeps startup chemistry small and beats the local service rush.
Closing — deadline November 2
Hold the cover until October 23, then winterize by November 2, a week ahead of the December 22 freeze normal. Late and cold beats early and warm.
Estimated water temperature by month
Monthly averages of the site's water model run on Fremont's own normals — the shape of a typical year, not a forecast. The widget above shows where the current year actually sits.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 50° | 52° | 55° | 57° | 60° | 63° | 67° | 68° | 68° | 65° | 59° | 52° |
The curve peaks near 68°F — comfortable-water months here usually involve a heater or a solar cover.
Email me when Fremont hits the closing window
Data: NOAA 1991–2020 climate normals via Fremont (2.1 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.