Pool season · Maryland
Ellicott City Pool Season: the Year on One Bar
Last updated: July 15, 2026 · dates · water temp
One bar, one year, one Ellicott City 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 Ellicott City's swim season; the hollow teal run before it (April 13 to May 4) is when to open; the hollow amber run after is when to close, with October 15 as the deadline; gray is the covered season. Today's marker shows where you stand in that cycle right now.
The Ellicott City pool calendar
Opening — target April 20
Open by April 20 — a two-week head start on the May 4 crossing keeps startup chemistry small and beats the local service rush.
Closing — deadline October 15
The window opens October 5 once water leaves the algae zone; the model deadline is October 15, a week ahead of the November 7 freeze normal.
Estimated water temperature by month
This is Ellicott City'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° | 41° | 50° | 60° | 69° | 77° | 77° | 72° | 63° | 52° | 43° |
The curve peaks near 78°F — comfortable-water months here usually involve a heater or a solar cover.
Email me when Ellicott City hits the closing window
Data: NOAA 1991–2020 climate normals via Cylburn (11.0 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.