Pool season · Minnesota
St. Paul Pool Season: the Year on One Bar
Last updated: July 25, 2026 · dates · water temp
St. Paul'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.
St. Paul, MN — 61 swim days a yearThe bar compresses St. Paul's whole pool year into one lane rope: gray floats for the off-season, hollow teal for the May 1–May 22 opening window, solid teal for swim weeks, hollow amber for the closing stretch that ends September 30. Wherever the today marker sits, the nearest color change is your next appointment.
The St. Paul pool calendar
Opening — target May 8
Target May 8; the practical window runs May 1–May 22, and the 7-day mean crosses the 61°F threshold around May 22. Cold-water starts are the cheap ones.
Closing — deadline September 30
Hold the cover until September 20, then winterize by September 30, a week ahead of the October 16 freeze normal. Late and cold beats early and warm.
Estimated water temperature by month
Monthly averages of the site's water model run on St. Paul'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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 18° | 18° | 27° | 41° | 54° | 65° | 72° | 73° | 68° | 56° | 41° | 27° |
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 St. Cloud's pool season and Woodbury's — neighboring normals stations can shift the windows by a week or more. The full ranking lives on the Minnesota season index.
St. Paul pool season FAQ
When should I open my pool in St. Paul, MN?
The site model recommends opening by May 8 — about two weeks before St. Paul'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 St. Paul opening guide.
When should I close my pool in St. Paul?
Winterize by September 30. The model holds the deadline a week ahead of St. Paul's NOAA 50% first-freeze date, so the plumbing is protected before the first hard night. The full sequence is in the St. Paul closing guide.
How long is the swim season in St. Paul?
St. Paul averages 61 days a year with normal highs of 80°F or better — right on the statewide median. The Minnesota season index ranks all 10 covered cities by the same metric.
How warm does pool water get in St. Paul?
An unheated pool near St. Paul typically peaks around 73°F in high summer and bottoms out near 16°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 St. Paul hits the closing window
Data: NOAA 1991–2020 climate normals via St Paul Downtown Airport (2.6 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.