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Pool season · Indiana

Indianapolis Pool Season: the Year on One Bar

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

Indianapolis'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.

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 Indianapolis'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 Indianapolis pool calendar

April 28open by
October 8close by
8780°F+ days
74°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 21 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 Indianapolis water runs about 26°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

This is Indianapolis'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.

Site-model seasonal water estimates for an unheated in-ground pool near Indianapolis SE Side — ±5°F, see methodology.
JanFebMarAprMayJunJulAugSepOctNovDec
28°28°36°46°58°68°74°74°70°60°47°36°

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 Indianapolis SE Side (5.9 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.