Pool season · California
San Bernardino Pool Season: the Year on One Bar
Last updated: July 25, 2026 · dates · water temp
San Bernardino'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.
San Bernardino, CA — 166 swim days a yearEach dot on the bar is one week of San Bernardino's typical year, colored by what the model says that week is for: gray weeks are off-season, hollow teal marks the opening window (March 22–April 12), solid teal is swim season, and hollow amber is the closing window ending November 23. The black marker is today — its position against the colors is the entire executive summary.
The San Bernardino pool calendar
Opening — target March 29
Open by March 29 — a two-week head start on the April 12 crossing keeps startup chemistry small and beats the local service rush.
Closing — deadline November 23
The window opens November 13 once water leaves the algae zone; the model deadline is November 23, a week ahead of the December 19 freeze normal.
Estimated water temperature by month
Monthly averages of the site's water model run on San Bernardino'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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 53° | 54° | 56° | 60° | 64° | 69° | 77° | 80° | 78° | 72° | 64° | 56° |
Warmest water typically August–September (peaking near 80°F); heaters and covers shift any month up.
Every station tells its own story: compare this curve with Salinas's pool season and San Buenaventura's — neighboring normals stations can shift the windows by a week or more. The full ranking lives on the California season index.
San Bernardino pool season FAQ
When should I open my pool in San Bernardino, CA?
Open by March 29 — the model places San Bernardino's 61°F crossing about two weeks later, and every warm day you wait pushes the water toward the 65°F algae zone. The San Bernardino opening guide has the 12-step sequence.
When should I close my pool in San Bernardino?
Close by November 23: cool water keeps its winter chemistry, but freeze damage is the hard stop. The San Bernardino closing guide sequences the work backward from that date.
How long is the swim season in San Bernardino?
San Bernardino averages 166 days a year with normal highs of 80°F or better — right on the statewide median. The California season index ranks all 147 covered cities by the same metric.
How warm does pool water get in San Bernardino?
An unheated pool near San Bernardino typically peaks around 80°F in high summer and bottoms out near 53°F in winter, spending roughly 2 months at or above the 78°F comfort line most swimmers prefer. The month-by-month curve above shows the whole cycle; the methodology page explains the ±5°F error bars.
Email me when San Bernardino hits the closing window
Data: NOAA 1991–2020 climate normals via Redlands (9.2 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.