Pool season · Michigan
Troy Pool Season: the Year on One Bar
Last updated: July 25, 2026 · dates · water temp
This is the one-page view of Troy'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.
Troy, MI — 63 swim days a yearThe bar compresses Troy's whole pool year into one lane rope: gray floats for the off-season, hollow teal for the April 30–May 21 opening window, solid teal for swim weeks, hollow amber for the closing stretch that ends October 3. Wherever the today marker sits, the nearest color change is your next appointment.
The Troy pool calendar
Opening — target May 7
Target May 7; the practical window runs April 30–May 21, and the 7-day mean crosses the 61°F threshold around May 21. Cold-water starts are the cheap ones.
Closing — deadline October 3
Hold the cover until September 23, then winterize by October 3, a week ahead of the October 22 freeze normal. Late and cold beats early and warm.
Estimated water temperature by month
This is Troy'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.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 27° | 24° | 31° | 42° | 54° | 65° | 71° | 72° | 68° | 58° | 45° | 35° |
The curve peaks near 73°F — comfortable-water months here usually involve a heater or a solar cover.
Every station tells its own story: compare this curve with Sterling Heights's pool season and Warren's — neighboring normals stations can shift the windows by a week or more. The full ranking lives on the Michigan season index.
Troy pool season FAQ
When should I open my pool in Troy, MI?
Target May 7. That date backs off two weeks from the day Troy's 7-day mean temperature reaches 61°F, so you start up in cold, algae-resistant water. Work the full checklist in the Troy opening guide.
When should I close my pool in Troy?
The closing deadline is October 3 — late enough that the water has cooled out of the algae zone, early enough to beat Troy's first-freeze normal by about a week. See the Troy closing guide for the winterizing steps.
How long is the swim season in Troy?
Troy averages 63 days a year with normal highs of 80°F or better — right on the statewide median. The Michigan season index ranks all 23 covered cities by the same metric.
How warm does pool water get in Troy?
An unheated pool near Troy typically peaks around 73°F in high summer and bottoms out near 24°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 Troy hits the closing window
Data: NOAA 1991–2020 climate normals via Pontiac Wwtp (6.8 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.