Pool season · California
Berkeley Pool Season: the Year on One Bar
Last updated: July 25, 2026 · dates · water temp
This is the one-page view of Berkeley'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.
Berkeley, CA — 0 swim days a yearEach dot on the bar is one week of Berkeley's typical year, colored by what the model says that week is for: gray weeks are off-season, hollow teal marks the opening window (May 7–May 28), solid teal is swim season, and hollow amber is the closing window ending November 5. The black marker is today — its position against the colors is the entire executive summary.
The Berkeley pool calendar
Opening — target May 14
Target May 14; the practical window runs May 7–May 28, and the 7-day mean crosses the 61°F threshold around May 28. 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 January 1 freeze normal. Late and cold beats early and warm.
Estimated water temperature by month
Monthly averages of the site's water model run on Berkeley'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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 51° | 52° | 54° | 56° | 58° | 62° | 64° | 64° | 65° | 64° | 59° | 53° |
The curve peaks near 65°F — comfortable-water months here usually involve a heater or a solar cover.
Every station tells its own story: compare this curve with Bellflower's pool season and Brentwood's — neighboring normals stations can shift the windows by a week or more. The full ranking lives on the California season index.
Berkeley pool season FAQ
When should I open my pool in Berkeley, CA?
Target May 14. That date backs off two weeks from the day Berkeley's 7-day mean temperature reaches 61°F, so you start up in cold, algae-resistant water. Work the full checklist in the Berkeley opening guide.
When should I close my pool in Berkeley?
The closing deadline is November 5 — late enough that the water has cooled out of the algae zone, early enough to beat Berkeley's first-freeze normal by about a week. See the Berkeley closing guide for the winterizing steps.
How long is the swim season in Berkeley?
Berkeley averages 0 days a year with normal highs of 80°F or better — about 43 days later than the California median. The California season index ranks all 147 covered cities by the same metric.
How warm does pool water get in Berkeley?
An unheated pool near Berkeley typically peaks around 65°F in high summer and bottoms out near 50°F in winter, never quite reaching the 78°F comfort line without a heater or solar cover. The month-by-month curve above shows the whole cycle; the methodology page explains the ±5°F error bars.
Email me when Berkeley hits the closing window
Data: NOAA 1991–2020 climate normals via Berkeley (0.9 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.