Pool season · Michigan
Holland Pool Season: the Year on One Bar
Last updated: July 25, 2026 · dates · water temp
One bar, one year, one Holland 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.
Holland, MI — 59 swim days a yearEach dot on the bar is one week of Holland'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 3–May 24), solid teal is swim season, and hollow amber is the closing window ending October 1. The black marker is today — its position against the colors is the entire executive summary.
The Holland pool calendar
Opening — target May 10
Open by May 10 — a two-week head start on the May 24 crossing keeps startup chemistry small and beats the local service rush.
Closing — deadline October 1
The window opens September 21 once water leaves the algae zone; the model deadline is October 1, a week ahead of the October 21 freeze normal.
Estimated water temperature by month
Monthly averages of the site's water model run on Holland's own normals — the shape of a typical year, not a forecast. The widget above shows where the current year actually sits.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 28° | 26° | 32° | 42° | 53° | 64° | 71° | 71° | 67° | 57° | 46° | 36° |
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 Grand Rapids's pool season and Jackson's — neighboring normals stations can shift the windows by a week or more. The full ranking lives on the Michigan season index.
Holland pool season FAQ
When should I open my pool in Holland, MI?
The site model recommends opening by May 10 — about two weeks before Holland'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 Holland opening guide.
When should I close my pool in Holland?
Winterize by October 1. The model holds the deadline a week ahead of Holland's NOAA 50% first-freeze date, so the plumbing is protected before the first hard night. The full sequence is in the Holland closing guide.
How long is the swim season in Holland?
Holland averages 59 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 Holland?
An unheated pool near Holland typically peaks around 72°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.
Email me when Holland hits the closing window
Data: NOAA 1991–2020 climate normals via Holland Tulip City Airport (1.5 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.