PoolWindow

Pool season · Indiana

Fishers Pool Season: the Year on One Bar

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

This is the one-page view of Fishers's pool year: both model windows, the estimated water-temperature curve, and today's live position on the season bar. The detailed checklists live on the opening and closing guides; this page is the calendar you check between them.

Cool blue pool in a short-season northern climateFishers, IN — 89 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 Fishers'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 24–May 15), solid teal is swim season, and hollow amber is the closing window ending October 8. The black marker is today — its position against the colors is the entire executive summary.

The Fishers pool calendar

May 1open by
October 8close by
8980°F+ days
74°Fwater peak

Opening — target May 1

Target May 1; the practical window runs April 24–May 15, and the 7-day mean crosses the 61°F threshold around May 15. Cold-water starts are the cheap ones.

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 Fishers water runs about 27°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 Fishers'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.

20°30°40°50°60°70°80°90°JanFebMarAprMayJunJulAugSepOctNovDec65° algae zone58° swimmable startopen May 1close Oct 874°F peak27°F floor
Site-model seasonal water estimates for an unheated in-ground pool near Carmel 3 E — ±5°F, see methodology.
JanFebMarAprMayJunJulAugSepOctNovDec
28°28°35°46°57°67°73°74°70°60°47°36°

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

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

Fishers pool season FAQ

When should I open my pool in Fishers, IN?

The site model recommends opening by May 1 — about two weeks before Fishers'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 Fishers opening guide.

When should I close my pool in Fishers?

Winterize by October 8. The model holds the deadline a week ahead of Fishers's NOAA 50% first-freeze date, so the plumbing is protected before the first hard night. The full sequence is in the Fishers closing guide.

How long is the swim season in Fishers?

Fishers averages 89 days a year with normal highs of 80°F or better — right on the statewide median. The Indiana season index ranks all 13 covered cities by the same metric.

How warm does pool water get in Fishers?

An unheated pool near Fishers typically peaks around 74°F in high summer and bottoms out near 27°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.

Data: NOAA 1991–2020 climate normals via Carmel 3 E (4.9 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.