Pool season · California
Hawthorne Pool Season: the Year on One Bar
Last updated: July 15, 2026 · dates · water temp
Hawthorne'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.
Each dot on the bar is one week of Hawthorne'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 8–March 29), solid teal is swim season, and hollow amber is the closing window ending December 2. The black marker is today — its position against the colors is the entire executive summary.
The Hawthorne pool calendar
Opening — target March 15
Target March 15; the practical window runs March 8–March 29, and the 7-day mean crosses the 61°F threshold around March 29. Cold-water starts are the cheap ones.
Closing — deadline December 2
The window opens November 22 once water leaves the algae zone; the model deadline is December 2, a week ahead of the January 5 freeze normal.
Estimated water temperature by month
This is Hawthorne'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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 58° | 58° | 60° | 61° | 64° | 66° | 70° | 72° | 72° | 70° | 66° | 59° |
The curve peaks near 72°F — comfortable-water months here usually involve a heater or a solar cover.
Email me when Hawthorne hits the closing window
Data: NOAA 1991–2020 climate normals via Hawthorne Municipal Airport (0.9 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.