PoolWindow

Pool season · Ohio

Middletown Pool Season: the Year on One Bar

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

One bar, one year, one Middletown 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 Middletown's whole pool year into one lane rope: gray floats for the off-season, hollow teal for the April 21–May 12 opening window, solid teal for swim weeks, hollow amber for the closing stretch that ends October 8. Wherever the today marker sits, the nearest color change is your next appointment.

The Middletown pool calendar

April 28open by
October 8close by
10080°F+ days
75°Fwater peak

Opening — target April 28

Open by April 28 — a two-week head start on the May 12 crossing keeps startup chemistry small and beats the local service rush.

Full opening guide

Closing — deadline October 8

The window opens September 28 once water leaves the algae zone; the model deadline is October 8, a week ahead of the October 19 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 Middletown water runs about 29°F at its winter floor and 75°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 Middletown'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 Franklin — ±5°F, see methodology.
JanFebMarAprMayJunJulAugSepOctNovDec
31°30°37°47°58°68°74°74°70°60°48°38°

The curve peaks near 75°F — comfortable-water months here usually involve a heater or a solar cover.

Data: NOAA 1991–2020 climate normals via Franklin (4.3 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.