PoolWindow

Pool season · California

Redwood City Pool Season: the Year on One Bar

Last updated: July 15, 2026 · dates · water temp

This is the one-page view of Redwood City'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 Redwood City'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 21–May 12), solid teal is swim season, and hollow amber is the closing window ending November 1. The black marker is today — its position against the colors is the entire executive summary.

The Redwood City pool calendar

April 28open by
November 1close by
8080°F+ days
69°Fwater peak

Opening — target April 28

Open by April 28 — a two-week head start on the May 12 crossing keeps startup chemistry small and beats the local service rush.

Full opening guide

Closing — deadline November 1

The window opens October 22 once water leaves the algae zone; the model deadline is November 1, a week ahead of the December 12 freeze normal.

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 Redwood City water runs about 49°F at its winter floor and 69°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 Redwood City'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 Redwood City — ±5°F, see methodology.
JanFebMarAprMayJunJulAugSepOctNovDec
49°51°54°56°60°64°68°69°68°65°58°51°

The curve peaks near 69°F — comfortable-water months here usually involve a heater or a solar cover.

Data: NOAA 1991–2020 climate normals via Redwood City (1.9 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.