PoolWindow

Pool season · Virginia

Alexandria Pool Season: the Year on One Bar

Last updated: July 25, 2026 · dates · water temp

Alexandria's whole pool calendar, condensed: when the water warms, when it cools, and where today falls between those edges. Use the opening guide and closing guide for the step-by-step work; keep this page for the dates.

Courtyard swimming pool at dawn in a temperate climateAlexandria, VA — 112 swim days a year
J F M A M J J A S O N D today (build date)

off-season opening window swim season closing window

Each dot on the bar is one week of Alexandria's typical year, colored by what the model says that week is for: gray weeks are off-season, hollow teal marks the opening window (April 3–April 24), solid teal is swim season, and hollow amber is the closing window ending October 25. The black marker is today — its position against the colors is the entire executive summary.

The Alexandria pool calendar

April 10open by
October 25close by
11280°F+ days
81°Fwater peak

Opening — target April 10

Open by April 10 — a two-week head start on the April 24 crossing keeps startup chemistry small and beats the local service rush.

Full opening guide

Closing — deadline October 25

The window opens October 15 once water leaves the algae zone; the model deadline is October 25, a week ahead of the November 18 freeze normal.

Full closing guide

Where the water sits today

SEASONAL VIEW

Estimated unheated pool water temp (site model, ±5°F). The live estimate loads in your browser from Open-Meteo air temperatures; in a typical year Alexandria water runs about 37°F at its winter floor and 81°F at its summer peak.

40 45 50 55 60 65 70 75 80 85 58 open 65 algae

Estimated water temperature by month

Monthly averages of the site's water model run on Alexandria's own normals — the shape of a typical year, not a forecast. The widget above shows where the current year actually sits.

30°40°50°60°70°80°90°JanFebMarAprMayJunJulAugSepOctNovDec65° algae zone58° swimmable startopen Apr 10close Oct 2581°F peak37°F floor
Site-model seasonal water estimates for an unheated in-ground pool near Washington Reagan Airport — ±5°F, see methodology.
JanFebMarAprMayJunJulAugSepOctNovDec
39°38°44°53°63°72°80°81°76°66°55°45°

Warmest water typically July–August (peaking near 81°F); heaters and covers shift any month up.

Every station tells its own story: compare this curve with Winchester's pool season and Arlington's — neighboring normals stations can shift the windows by a week or more. The full ranking lives on the Virginia season index.

Alexandria pool season FAQ

When should I open my pool in Alexandria, VA?

The site model recommends opening by April 10 — about two weeks before Alexandria'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 Alexandria opening guide.

When should I close my pool in Alexandria?

Winterize by October 25. The model holds the deadline a week ahead of Alexandria's NOAA 50% first-freeze date, so the plumbing is protected before the first hard night. The full sequence is in the Alexandria closing guide.

How long is the swim season in Alexandria?

Alexandria averages 112 days a year with normal highs of 80°F or better — right on the statewide median. The Virginia season index ranks all 16 covered cities by the same metric.

How warm does pool water get in Alexandria?

An unheated pool near Alexandria typically peaks around 81°F in high summer and bottoms out near 37°F in winter, spending roughly 2 months at or above the 78°F comfort line most swimmers prefer. The month-by-month curve above shows the whole cycle; the methodology page explains the ±5°F error bars.

Data: NOAA 1991–2020 climate normals via Washington Reagan Airport (3.5 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.