Pool season · Maryland
Waldorf Pool Season: the Year on One Bar
Last updated: July 15, 2026 · dates · water temp
One bar, one year, one Waldorf 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.
Reading it takes ten seconds: 52 dots, one per week. Solid teal is Waldorf's swim season; the hollow teal run before it (April 17 to May 8) is when to open; the hollow amber run after is when to close, with October 12 as the deadline; gray is the covered season. Today's marker shows where you stand in that cycle right now.
The Waldorf pool calendar
Opening — target April 24
Target April 24; the practical window runs April 17–May 8, and the 7-day mean crosses the 61°F threshold around May 8. Cold-water starts are the cheap ones.
Closing — deadline October 12
Hold the cover until October 2, then winterize by October 12, a week ahead of the October 27 freeze normal. Late and cold beats early and warm.
Estimated water temperature by month
This is Waldorf'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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 36° | 35° | 40° | 50° | 60° | 67° | 75° | 75° | 71° | 61° | 51° | 42° |
The curve peaks near 76°F — comfortable-water months here usually involve a heater or a solar cover.
Email me when Waldorf hits the closing window
Data: NOAA 1991–2020 climate normals via Mechanicsville 5 NE (13.2 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.