PoolWindow

Pool season · Michigan

Port Huron Pool Season: the Year on One Bar

Last updated: July 25, 2026 · dates · water temp

One bar, one year, one Port Huron 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.

Cool blue pool in a short-season northern climatePort Huron, MI — 47 swim days a year
J F M A M J J A S O N D today (build date)

off-season opening window swim season closing window

The bar compresses Port Huron's whole pool year into one lane rope: gray floats for the off-season, hollow teal for the May 5–May 26 opening window, solid teal for swim weeks, hollow amber for the closing stretch that ends October 6. Wherever the today marker sits, the nearest color change is your next appointment.

The Port Huron pool calendar

May 12open by
October 6close by
4780°F+ days
73°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 October 6

Hold the cover until September 26, then winterize by October 6, a week ahead of the November 3 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 Port Huron water runs about 25°F at its winter floor and 73°F at its summer peak.

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

Estimated water temperature by month

Monthly averages of the site's water model run on Port Huron's own normals — the shape of a typical year, not a forecast. The widget above shows where the current year actually sits.

10°20°30°40°50°60°70°80°JanFebMarAprMayJunJulAugSepOctNovDec65° algae zone58° swimmable startopen May 12close Oct 673°F peak25°F floor
Site-model seasonal water estimates for an unheated in-ground pool near Port Huron — ±5°F, see methodology.
JanFebMarAprMayJunJulAugSepOctNovDec
28°25°31°41°53°63°72°73°69°59°47°36°

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 Muskegon's pool season and Rochester Hills's — neighboring normals stations can shift the windows by a week or more. The full ranking lives on the Michigan season index.

Port Huron pool season FAQ

When should I open my pool in Port Huron, MI?

Open by May 12 — the model places Port Huron's 61°F crossing about two weeks later, and every warm day you wait pushes the water toward the 65°F algae zone. The Port Huron opening guide has the 12-step sequence.

When should I close my pool in Port Huron?

Close by October 6: cool water keeps its winter chemistry, but freeze damage is the hard stop. The Port Huron closing guide sequences the work backward from that date.

How long is the swim season in Port Huron?

Port Huron averages 47 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 Port Huron?

An unheated pool near Port Huron typically peaks around 73°F in high summer and bottoms out near 25°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.

Data: NOAA 1991–2020 climate normals via Port Huron (1.1 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.