PoolWindow

Pool season · Michigan

Southfield Pool Season: the Year on One Bar

Last updated: July 15, 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.

J F M A M J J A S O N D today (build date)

off-season opening window swim season closing window

Each 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

May 12open by
September 29close by
6280°F+ days
72°Fwater peak

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.

Full opening guide

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.

Full closing guide

Where the water sits today

SEASONAL VIEW

Estimated unheated pool water temp (site model, ±5°F). The live estimate loads in your browser from Open-Meteo air temperatures; in a typical year Southfield water runs about 23°F at its winter floor and 72°F at its summer peak.

40 45 50 55 60 65 70 75 80 85 58 open 65 algae

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.

Site-model seasonal water estimates for an unheated in-ground pool near Farmington — ±5°F, see methodology.
JanFebMarAprMayJunJulAugSepOctNovDec
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.

Data: NOAA 1991–2020 climate normals via Farmington (5.2 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.