Pool season · California
Modesto Pool Season: the Year on One Bar
Last updated: July 15, 2026 · dates · water temp
Modesto'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 Modesto'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 26–April 16), solid teal is swim season, and hollow amber is the closing window ending November 7. The black marker is today — its position against the colors is the entire executive summary.
The Modesto pool calendar
Opening — target April 2
Target April 2; the practical window runs March 26–April 16, and the 7-day mean crosses the 61°F threshold around April 16. Cold-water starts are the cheap ones.
Closing — deadline November 7
Hold the cover until October 28, then winterize by November 7, a week ahead of the December 5 freeze normal. Late and cold beats early and warm.
Estimated water temperature by month
This is Modesto'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° | 50° | 55° | 59° | 65° | 72° | 77° | 79° | 76° | 70° | 60° | 50° |
Warmest water typically August–August (peaking near 79°F); heaters and covers shift any month up.
Email me when Modesto hits the closing window
Data: NOAA 1991–2020 climate normals via Modesto City Co Airport (3.0 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.