PoolWindow

Pool season · Wisconsin

Eau Claire Pool Season: the Year on One Bar

Last updated: July 15, 2026 · dates · water temp

Eau Claire'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.

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 Eau Claire's swim season; the hollow teal run before it (April 30 to May 21) is when to open; the hollow amber run after is when to close, with September 27 as the deadline; gray is the covered season. Today's marker shows where you stand in that cycle right now.

The Eau Claire pool calendar

May 7open by
September 27close by
5280°F+ days
73°Fwater peak

Opening — target May 7

Target May 7; the practical window runs April 30–May 21, and the 7-day mean crosses the 61°F threshold around May 21. Cold-water starts are the cheap ones.

Full opening guide

Closing — deadline September 27

Hold the cover until September 17, then winterize by September 27, a week ahead of the October 14 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 Eau Claire water runs about 16°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 Eau Claire's own normals — the shape of a typical year, not a forecast. The widget above shows where the current year actually sits.

Site-model seasonal water estimates for an unheated in-ground pool near Eau Claire 3sw — ±5°F, see methodology.
JanFebMarAprMayJunJulAugSepOctNovDec
18°17°27°40°53°65°71°72°66°56°41°28°

The curve peaks near 73°F — comfortable-water months here usually involve a heater or a solar cover.

Data: NOAA 1991–2020 climate normals via Eau Claire 3sw (2.4 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.