PoolWindow

Pool season · California

Berkeley Pool Season: the Year on One Bar

Last updated: July 15, 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.

J F M A M J J A S O N D today (build date)

off-season opening window swim season closing window

Each 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

May 14open by
November 5close by
080°F+ days
65°Fwater peak

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.

Full opening guide

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.

Full closing guide

Where the water sits today

SEASONAL VIEW

Estimated unheated pool water temp (site model, ±5°F). The live estimate loads in your browser from Open-Meteo air temperatures; in a typical year Berkeley water runs about 50°F at its winter floor and 65°F at its summer peak.

40 45 50 55 60 65 70 75 80 85 58 open 65 algae

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.

Site-model seasonal water estimates for an unheated in-ground pool near Berkeley — ±5°F, see methodology.
JanFebMarAprMayJunJulAugSepOctNovDec
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.

Data: NOAA 1991–2020 climate normals via Berkeley (0.9 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.