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Pool season · Oregon

Eugene Pool Season: the Year on One Bar

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

Eugene'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 climateEugene, OR — 71 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 Eugene's swim season; the hollow teal run before it (May 28 to June 18) is when to open; the hollow amber run after is when to close, with October 3 as the deadline; gray is the covered season. Today's marker shows where you stand in that cycle right now.

The Eugene pool calendar

June 4open by
October 3close by
7180°F+ days
69°Fwater peak

Opening — target June 4

Target June 4; the practical window runs May 28–June 18, and the 7-day mean crosses the 61°F threshold around June 18. Cold-water starts are the cheap ones.

Full opening guide

Closing — deadline October 3

The window opens September 23 once water leaves the algae zone; the model deadline is October 3, a week ahead of the October 23 freeze normal.

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 Eugene water runs about 40°F at its winter floor and 69°F at its summer peak.

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

Estimated water temperature by month

This is Eugene's typical-year water curve: the same EWMA model as the live widget, run on the 1991–2020 normals instead of this week's weather.

30°40°50°60°70°80°JanFebMarAprMayJunJulAugSepOctNovDec65° algae zone58° swimmable startopen Jun 4close Oct 369°F peak40°F floor
Site-model seasonal water estimates for an unheated in-ground pool near Eugene Mahlon Sweet Airport — ±5°F, see methodology.
JanFebMarAprMayJunJulAugSepOctNovDec
41°42°45°49°54°58°65°69°66°58°49°42°

The curve peaks near 69°F — comfortable-water months here usually involve a heater or a solar cover.

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

Eugene pool season FAQ

When should I open my pool in Eugene, OR?

Open by June 4 — the model places Eugene's 61°F crossing about two weeks later, and every warm day you wait pushes the water toward the 65°F algae zone. The Eugene opening guide has the 12-step sequence.

When should I close my pool in Eugene?

Close by October 3: cool water keeps its winter chemistry, but freeze damage is the hard stop. The Eugene closing guide sequences the work backward from that date.

How long is the swim season in Eugene?

Eugene averages 71 days a year with normal highs of 80°F or better — about 11 days later than the Oregon median. The Oregon season index ranks all 8 covered cities by the same metric.

How warm does pool water get in Eugene?

An unheated pool near Eugene typically peaks around 69°F in high summer and bottoms out near 40°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 Eugene Mahlon Sweet Airport (7.1 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.