Pool season · Michigan
Jackson Pool Season: the Year on One Bar
Last updated: July 25, 2026 · dates · water temp
This is the one-page view of Jackson'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.
Jackson, MI — 64 swim days a yearReading it takes ten seconds: 52 dots, one per week. Solid teal is Jackson's swim season; the hollow teal run before it (May 2 to May 23) is when to open; the hollow amber run after is when to close, with September 30 as the deadline; gray is the covered season. Today's marker shows where you stand in that cycle right now.
The Jackson pool calendar
Opening — target May 9
Open by May 9 — a two-week head start on the May 23 crossing keeps startup chemistry small and beats the local service rush.
Closing — deadline September 30
The window opens September 20 once water leaves the algae zone; the model deadline is September 30, a week ahead of the October 14 freeze normal.
Estimated water temperature by month
This is Jackson'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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 26° | 25° | 31° | 43° | 54° | 64° | 71° | 71° | 67° | 57° | 45° | 34° |
The curve peaks near 72°F — comfortable-water months here usually involve a heater or a solar cover.
Every station tells its own story: compare this curve with Holland's pool season and Kalamazoo's — neighboring normals stations can shift the windows by a week or more. The full ranking lives on the Michigan season index.
Jackson pool season FAQ
When should I open my pool in Jackson, MI?
Open by May 9 — the model places Jackson's 61°F crossing about two weeks later, and every warm day you wait pushes the water toward the 65°F algae zone. The Jackson opening guide has the 12-step sequence.
When should I close my pool in Jackson?
Close by September 30: cool water keeps its winter chemistry, but freeze damage is the hard stop. The Jackson closing guide sequences the work backward from that date.
How long is the swim season in Jackson?
Jackson averages 64 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 Jackson?
An unheated pool near Jackson typically peaks around 72°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 Jackson hits the closing window
Data: NOAA 1991–2020 climate normals via Jackson Reynolds Field (3.6 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.