Pool season · Pennsylvania
Allentown Pool Season: the Year on One Bar
Last updated: July 15, 2026 · dates · water temp
One bar, one year, one Allentown 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 Allentown's swim season; the hollow teal run before it (April 22 to May 13) is when to open; the hollow amber run after is when to close, with October 9 as the deadline; gray is the covered season. Today's marker shows where you stand in that cycle right now.
The Allentown pool calendar
Opening — target April 29
Open by April 29 — a two-week head start on the May 13 crossing keeps startup chemistry small and beats the local service rush.
Closing — deadline October 9
The window opens September 29 once water leaves the algae zone; the model deadline is October 9, a week ahead of the October 24 freeze normal.
Estimated water temperature by month
This is Allentown'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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 32° | 30° | 37° | 47° | 58° | 67° | 74° | 75° | 70° | 60° | 49° | 39° |
The curve peaks near 76°F — comfortable-water months here usually involve a heater or a solar cover.
Email me when Allentown hits the closing window
Data: NOAA 1991–2020 climate normals via Allentown International Airport (4.0 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.