PoolWindow

Pool season · Minnesota

St. Cloud Pool Season: the Year on One Bar

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

St. Cloud's whole pool calendar, condensed: when the water warms, when it cools, and where today falls between those edges. Use the opening guide and closing guide for the step-by-step work; keep this page for the dates.

Cool blue pool in a short-season northern climateSt. Cloud, MN — 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

Reading it takes ten seconds: 52 dots, one per week. Solid teal is St. Cloud's swim season; the hollow teal run before it (May 9 to May 30) is when to open; the hollow amber run after is when to close, with September 22 as the deadline; gray is the covered season. Today's marker shows where you stand in that cycle right now.

The St. Cloud pool calendar

May 16open by
September 22close by
4780°F+ days
70°Fwater peak

Opening — target May 16

Target May 16; the practical window runs May 9–May 30, and the 7-day mean crosses the 61°F threshold around May 30. Cold-water starts are the cheap ones.

Full opening guide

Closing — deadline September 22

Hold the cover until September 12, then winterize by September 22, a week ahead of the September 30 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 St. Cloud water runs about 12°F at its winter floor and 70°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 St. Cloud'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 16close Sep 2270°F peak12°F floor
Site-model seasonal water estimates for an unheated in-ground pool near St Cloud Regional Airport — ±5°F, see methodology.
JanFebMarAprMayJunJulAugSepOctNovDec
14°13°23°37°51°62°69°69°64°53°38°24°

The curve peaks near 70°F — comfortable-water months here usually involve a heater or a solar cover.

Every station tells its own story: compare this curve with Rochester's pool season and St. Paul's — neighboring normals stations can shift the windows by a week or more. The full ranking lives on the Minnesota season index.

St. Cloud pool season FAQ

When should I open my pool in St. Cloud, MN?

Target May 16. That date backs off two weeks from the day St. Cloud's 7-day mean temperature reaches 61°F, so you start up in cold, algae-resistant water. Work the full checklist in the St. Cloud opening guide.

When should I close my pool in St. Cloud?

The closing deadline is September 22 — late enough that the water has cooled out of the algae zone, early enough to beat St. Cloud's first-freeze normal by about a week. See the St. Cloud closing guide for the winterizing steps.

How long is the swim season in St. Cloud?

St. Cloud averages 47 days a year with normal highs of 80°F or better — about 6 days later than the Minnesota median. The Minnesota season index ranks all 10 covered cities by the same metric.

How warm does pool water get in St. Cloud?

An unheated pool near St. Cloud typically peaks around 70°F in high summer and bottoms out near 12°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 St Cloud Regional Airport (5.8 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.