Pool season · Michigan
Kalamazoo Pool Season: the Year on One Bar
Last updated: July 15, 2026 · dates · water temp
One bar, one year, one Kalamazoo 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.
Each dot on the bar is one week of Kalamazoo'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 30–May 21), solid teal is swim season, and hollow amber is the closing window ending October 2. The black marker is today — its position against the colors is the entire executive summary.
The Kalamazoo 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 2
The window opens September 22 once water leaves the algae zone; the model deadline is October 2, a week ahead of the October 18 freeze normal.
Estimated water temperature by month
This is Kalamazoo'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° | 25° | 32° | 43° | 55° | 65° | 72° | 72° | 68° | 57° | 45° | 35° |
The curve peaks near 72°F — comfortable-water months here usually involve a heater or a solar cover.
Email me when Kalamazoo hits the closing window
Data: NOAA 1991–2020 climate normals via Kalamazoo Battle Ck International Airport (3.4 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.