Pool season · Michigan
Southfield Pool Season: the Year on One Bar
Last updated: July 25, 2026 · dates · water temp
This is the one-page view of Southfield'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.
Southfield, MI — 62 swim days a yearEach dot on the bar is one week of Southfield's typical year, colored by what the model says that week is for: gray weeks are off-season, hollow teal marks the opening window (May 5–May 26), solid teal is swim season, and hollow amber is the closing window ending September 29. The black marker is today — its position against the colors is the entire executive summary.
The Southfield pool calendar
Opening — target May 12
Target May 12; the practical window runs May 5–May 26, and the 7-day mean crosses the 61°F threshold around May 26. Cold-water starts are the cheap ones.
Closing — deadline September 29
Hold the cover until September 19, then winterize by September 29, a week ahead of the October 17 freeze normal. Late and cold beats early and warm.
Estimated water temperature by month
This is Southfield'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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 25° | 23° | 29° | 40° | 52° | 63° | 70° | 71° | 66° | 56° | 44° | 33° |
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 South Lyon's pool season and Sterling Heights's — neighboring normals stations can shift the windows by a week or more. The full ranking lives on the Michigan season index.
Southfield pool season FAQ
When should I open my pool in Southfield, MI?
The site model recommends opening by May 12 — about two weeks before Southfield'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 Southfield opening guide.
When should I close my pool in Southfield?
Winterize by September 29. The model holds the deadline a week ahead of Southfield's NOAA 50% first-freeze date, so the plumbing is protected before the first hard night. The full sequence is in the Southfield closing guide.
How long is the swim season in Southfield?
Southfield averages 62 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 Southfield?
An unheated pool near Southfield typically peaks around 72°F in high summer and bottoms out near 23°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 Southfield hits the closing window
Data: NOAA 1991–2020 climate normals via Farmington (5.2 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.