Pool season · Indiana
Terre Haute Pool Season: the Year on One Bar
Last updated: July 25, 2026 · dates · water temp
One bar, one year, one Terre Haute 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.
Terre Haute, IN — 126 swim days a yearEach dot on the bar is one week of Terre Haute'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 8–April 29), solid teal is swim season, and hollow amber is the closing window ending October 12. The black marker is today — its position against the colors is the entire executive summary.
The Terre Haute pool calendar
Opening — target April 15
Open by April 15 — a two-week head start on the April 29 crossing keeps startup chemistry small and beats the local service rush.
Closing — deadline October 12
The window opens October 6 once water leaves the algae zone; the model deadline is October 12, a week ahead of the October 19 freeze normal.
Estimated water temperature by month
Monthly averages of the site's water model run on Terre Haute's own normals — the shape of a typical year, not a forecast. The widget above shows where the current year actually sits.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 31° | 31° | 39° | 51° | 62° | 71° | 78° | 78° | 74° | 63° | 50° | 39° |
Warmest water typically July–August (peaking near 78°F); heaters and covers shift any month up.
Every station tells its own story: compare this curve with South Bend's pool season and Anderson's — neighboring normals stations can shift the windows by a week or more. The full ranking lives on the Indiana season index.
Terre Haute pool season FAQ
When should I open my pool in Terre Haute, IN?
The site model recommends opening by April 15 — about two weeks before Terre Haute'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 Terre Haute opening guide.
When should I close my pool in Terre Haute?
Winterize by October 12. The model holds the deadline a week ahead of Terre Haute's NOAA 50% first-freeze date, so the plumbing is protected before the first hard night. The full sequence is in the Terre Haute closing guide.
How long is the swim season in Terre Haute?
Terre Haute averages 126 days a year with normal highs of 80°F or better — about 16 days earlier than the Indiana median. The Indiana season index ranks all 13 covered cities by the same metric.
How warm does pool water get in Terre Haute?
An unheated pool near Terre Haute typically peaks around 78°F in high summer and bottoms out near 30°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.
Email me when Terre Haute hits the closing window
Data: NOAA 1991–2020 climate normals via Terre Haute Indiana State (1.8 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.