Pool season · California
Livermore Pool Season: the Year on One Bar
Last updated: July 25, 2026 · dates · water temp
This is the one-page view of Livermore'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.
Livermore, CA — 129 swim days a yearEach dot on the bar is one week of Livermore'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 12–May 3), solid teal is swim season, and hollow amber is the closing window ending November 3. The black marker is today — its position against the colors is the entire executive summary.
The Livermore pool calendar
Opening — target April 19
Target April 19; the practical window runs April 12–May 3, and the 7-day mean crosses the 61°F threshold around May 3. Cold-water starts are the cheap ones.
Closing — deadline November 3
Hold the cover until October 24, then winterize by November 3, a week ahead of the December 2 freeze normal. Late and cold beats early and warm.
Estimated water temperature by month
This is Livermore's typical-year water curve: the same EWMA model as the live widget, run on the 1991–2020 normals instead of this week's weather.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 47° | 49° | 53° | 56° | 61° | 66° | 72° | 73° | 72° | 67° | 58° | 50° |
The curve peaks near 73°F — comfortable-water months here usually involve a heater or a solar cover.
Every station tells its own story: compare this curve with Lancaster's pool season and Lodi's — neighboring normals stations can shift the windows by a week or more. The full ranking lives on the California season index.
Livermore pool season FAQ
When should I open my pool in Livermore, CA?
Open by April 19 — the model places Livermore's 61°F crossing about two weeks later, and every warm day you wait pushes the water toward the 65°F algae zone. The Livermore opening guide has the 12-step sequence.
When should I close my pool in Livermore?
Close by November 3: cool water keeps its winter chemistry, but freeze damage is the hard stop. The Livermore closing guide sequences the work backward from that date.
How long is the swim season in Livermore?
Livermore averages 129 days a year with normal highs of 80°F or better — about 18 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 Livermore?
An unheated pool near Livermore typically peaks around 73°F in high summer and bottoms out near 47°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 Livermore hits the closing window
Data: NOAA 1991–2020 climate normals via Livermore (3.0 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.