PoolWindow

Pool season · Pennsylvania

Lebanon Pool Season: the Year on One Bar

Last updated: July 15, 2026 · dates · water temp

One bar, one year, one Lebanon 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.

J F M A M J J A S O N D today (build date)

off-season opening window swim season closing window

The bar compresses Lebanon's whole pool year into one lane rope: gray floats for the off-season, hollow teal for the April 24–May 15 opening window, solid teal for swim weeks, hollow amber for the closing stretch that ends October 7. Wherever the today marker sits, the nearest color change is your next appointment.

The Lebanon pool calendar

May 1open by
October 7close by
7980°F+ days
74°Fwater peak

Opening — target May 1

Open by May 1 — a two-week head start on the May 15 crossing keeps startup chemistry small and beats the local service rush.

Full opening guide

Closing — deadline October 7

Hold the cover until September 27, then winterize by October 7, a week ahead of the October 25 freeze normal. Late and cold beats early and warm.

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 Lebanon water runs about 29°F at its winter floor and 74°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 Lebanon's own normals — the shape of a typical year, not a forecast. The widget above shows where the current year actually sits.

Site-model seasonal water estimates for an unheated in-ground pool near Lebanon 2 W — ±5°F, see methodology.
JanFebMarAprMayJunJulAugSepOctNovDec
31°30°36°46°57°66°73°74°70°60°48°38°

The curve peaks near 74°F — comfortable-water months here usually involve a heater or a solar cover.

Data: NOAA 1991–2020 climate normals via Lebanon 2 W (2.4 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.