Pool season · California
Rocklin Pool Season: the Year on One Bar
Last updated: July 15, 2026 · dates · water temp
Rocklin'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 Rocklin'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 13–May 4), solid teal is swim season, and hollow amber is the closing window ending November 4. The black marker is today — its position against the colors is the entire executive summary.
The Rocklin pool calendar
Opening — target April 20
Target April 20; the practical window runs April 13–May 4, and the 7-day mean crosses the 61°F threshold around May 4. Cold-water starts are the cheap ones.
Closing — deadline November 4
The window opens October 25 once water leaves the algae zone; the model deadline is November 4, a week ahead of the December 5 freeze normal.
Estimated water temperature by month
Monthly averages of the site's water model run on Rocklin'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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 46° | 48° | 51° | 54° | 61° | 68° | 76° | 78° | 76° | 69° | 58° | 49° |
Warmest water typically August–August (peaking near 79°F); heaters and covers shift any month up.
Email me when Rocklin hits the closing window
Data: NOAA 1991–2020 climate normals via Auburn (11.2 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.