Pool season · California
Vallejo Pool Season: the Year on One Bar
Last updated: July 15, 2026 · dates · water temp
Vallejo'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.
Each dot on the bar is one week of Vallejo's typical year, colored by what the model says that week is for: gray weeks are off-season, hollow teal marks the opening window (April 2–April 23), solid teal is swim season, and hollow amber is the closing window ending November 11. The black marker is today — its position against the colors is the entire executive summary.
The Vallejo pool calendar
Opening — target April 9
Open by April 9 — a two-week head start on the April 23 crossing keeps startup chemistry small and beats the local service rush.
Closing — deadline November 11
Hold the cover until November 1, then winterize by November 11, a week ahead of the December 27 freeze normal. Late and cold beats early and warm.
Estimated water temperature by month
Monthly averages of the site's water model run on Vallejo'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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 49° | 52° | 56° | 58° | 62° | 67° | 70° | 71° | 71° | 70° | 61° | 52° |
The curve peaks near 72°F — comfortable-water months here usually involve a heater or a solar cover.
Email me when Vallejo hits the closing window
Data: NOAA 1991–2020 climate normals via Vallejo (2.7 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.