Pool season · Maryland
Waldorf Pool Season: the Year on One Bar
Last updated: July 25, 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.
Waldorf, MD — 88 swim days a yearReading 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.
Every station tells its own story: compare this curve with Silver Spring's pool season and Baltimore's — neighboring normals stations can shift the windows by a week or more. The full ranking lives on the Maryland season index.
Waldorf pool season FAQ
When should I open my pool in Waldorf, MD?
The site model recommends opening by April 24 — about two weeks before Waldorf's 7-day mean temperature crosses 61°F, while the water is still too cold for algae. The step-by-step sequence is in the Waldorf opening guide.
When should I close my pool in Waldorf?
Winterize by October 12. The model holds the deadline a week ahead of Waldorf's NOAA 50% first-freeze date, so the plumbing is protected before the first hard night. The full sequence is in the Waldorf closing guide.
How long is the swim season in Waldorf?
Waldorf averages 88 days a year with normal highs of 80°F or better — about 4 days later than the Maryland median. The Maryland season index ranks all 9 covered cities by the same metric.
How warm does pool water get in Waldorf?
An unheated pool near Waldorf typically peaks around 76°F in high summer and bottoms out near 34°F in winter, never quite reaching the 78°F comfort line without a heater or solar cover. The month-by-month curve above shows the whole cycle; the methodology page explains the ±5°F error bars.
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.