Pool season · Washington
Marysville Pool Season: the Year on One Bar
Last updated: July 15, 2026 · dates · water temp
One bar, one year, one Marysville pool. The season bar below draws everything the model knows — opening window, prime season, closing window — against today's date, with the working details one click away on the opening and closing pages.
Each dot on the bar is one week of Marysville'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 28–June 18), solid teal is swim season, and hollow amber is the closing window ending September 21. The black marker is today — its position against the colors is the entire executive summary.
The Marysville pool calendar
Opening — target June 4
Target June 4; the practical window runs May 28–June 18, and the 7-day mean crosses the 61°F threshold around June 18. Cold-water starts are the cheap ones.
Closing — deadline September 21
Hold the cover until September 11, then winterize by September 21, a week ahead of the November 2 freeze normal. Late and cold beats early and warm.
Estimated water temperature by month
This is Marysville'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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 41° | 42° | 44° | 48° | 54° | 59° | 63° | 66° | 63° | 56° | 48° | 42° |
The curve peaks near 66°F — comfortable-water months here usually involve a heater or a solar cover.
Email me when Marysville hits the closing window
Data: NOAA 1991–2020 climate normals via Everett (7.5 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.