Pool season · Ohio
Cincinnati Pool Season: the Year on One Bar
Last updated: July 25, 2026 · dates · water temp
This is the one-page view of Cincinnati'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.
Cincinnati, OH — 105 swim days a yearReading it takes ten seconds: 52 dots, one per week. Solid teal is Cincinnati's swim season; the hollow teal run before it (April 15 to May 6) is when to open; the hollow amber run after is when to close, with October 13 as the deadline; gray is the covered season. Today's marker shows where you stand in that cycle right now.
The Cincinnati pool calendar
Opening — target April 22
Target April 22; the practical window runs April 15–May 6, and the 7-day mean crosses the 61°F threshold around May 6. Cold-water starts are the cheap ones.
Closing — deadline October 13
The window opens October 3 once water leaves the algae zone; the model deadline is October 13, a week ahead of the October 25 freeze normal.
Estimated water temperature by month
Monthly averages of the site's water model run on Cincinnati'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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 34° | 33° | 40° | 50° | 60° | 69° | 75° | 76° | 72° | 62° | 50° | 40° |
The curve peaks near 76°F — comfortable-water months here usually involve a heater or a solar cover.
Every station tells its own story: compare this curve with Canton's pool season and Cleveland's — neighboring normals stations can shift the windows by a week or more. The full ranking lives on the Ohio season index.
Cincinnati pool season FAQ
When should I open my pool in Cincinnati, OH?
The site model recommends opening by April 22 — about two weeks before Cincinnati'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 Cincinnati opening guide.
When should I close my pool in Cincinnati?
Winterize by October 13. The model holds the deadline a week ahead of Cincinnati's NOAA 50% first-freeze date, so the plumbing is protected before the first hard night. The full sequence is in the Cincinnati closing guide.
How long is the swim season in Cincinnati?
Cincinnati averages 105 days a year with normal highs of 80°F or better — about 10 days earlier than the Ohio median. The Ohio season index ranks all 14 covered cities by the same metric.
How warm does pool water get in Cincinnati?
An unheated pool near Cincinnati typically peaks around 76°F in high summer and bottoms out near 32°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 Cincinnati hits the closing window
Data: NOAA 1991–2020 climate normals via Cincinnati Lunken Airport (5.3 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.