Pool season · Kentucky
Louisville Pool Season: the Year on One Bar
Last updated: July 25, 2026 · dates · water temp
One bar, one year, one Louisville 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.
Louisville, KY — 113 swim days a yearThe bar compresses Louisville's whole pool year into one lane rope: gray floats for the off-season, hollow teal for the April 7–April 28 opening window, solid teal for swim weeks, hollow amber for the closing stretch that ends October 20. Wherever the today marker sits, the nearest color change is your next appointment.
The Louisville pool calendar
Opening — target April 14
Target April 14; the practical window runs April 7–April 28, and the 7-day mean crosses the 61°F threshold around April 28. Cold-water starts are the cheap ones.
Closing — deadline October 20
The window opens October 10 once water leaves the algae zone; the model deadline is October 20, a week ahead of the November 1 freeze normal.
Estimated water temperature by month
Monthly averages of the site's water model run on Louisville'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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 35° | 35° | 43° | 52° | 62° | 71° | 77° | 78° | 74° | 64° | 52° | 42° |
Warmest water typically August–August (peaking near 78°F); heaters and covers shift any month up.
Every station tells its own story: compare this curve with Lexington's pool season and Bowling Green's — neighboring normals stations can shift the windows by a week or more. The full ranking lives on the Kentucky season index.
Louisville pool season FAQ
When should I open my pool in Louisville, KY?
The site model recommends opening by April 14 — about two weeks before Louisville'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 Louisville opening guide.
When should I close my pool in Louisville?
Winterize by October 20. The model holds the deadline a week ahead of Louisville's NOAA 50% first-freeze date, so the plumbing is protected before the first hard night. The full sequence is in the Louisville closing guide.
How long is the swim season in Louisville?
Louisville averages 113 days a year with normal highs of 80°F or better — right on the statewide median. The Kentucky season index ranks all 4 covered cities by the same metric.
How warm does pool water get in Louisville?
An unheated pool near Louisville typically peaks around 78°F in high summer and bottoms out near 34°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 Louisville hits the closing window
Data: NOAA 1991–2020 climate normals via Louisville Wfo (3.5 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.