Pool season · Washington
Spokane Pool Season: the Year on One Bar
Last updated: July 25, 2026 · dates · water temp
Spokane'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.
Spokane, WA — 70 swim days a yearEach dot on the bar is one week of Spokane'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 16–June 6), solid teal is swim season, and hollow amber is the closing window ending September 27. The black marker is today — its position against the colors is the entire executive summary.
The Spokane pool calendar
Opening — target May 23
Target May 23; the practical window runs May 16–June 6, and the 7-day mean crosses the 61°F threshold around June 6. Cold-water starts are the cheap ones.
Closing — deadline September 27
The window opens September 17 once water leaves the algae zone; the model deadline is September 27, a week ahead of the October 15 freeze normal.
Estimated water temperature by month
Monthly averages of the site's water model run on Spokane'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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 31° | 33° | 38° | 45° | 53° | 60° | 68° | 72° | 66° | 55° | 43° | 34° |
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 Seattle's pool season and Spokane Valley's — neighboring normals stations can shift the windows by a week or more. The full ranking lives on the Washington season index.
Spokane pool season FAQ
When should I open my pool in Spokane, WA?
Target May 23. That date backs off two weeks from the day Spokane's 7-day mean temperature reaches 61°F, so you start up in cold, algae-resistant water. Work the full checklist in the Spokane opening guide.
When should I close my pool in Spokane?
The closing deadline is September 27 — late enough that the water has cooled out of the algae zone, early enough to beat Spokane's first-freeze normal by about a week. See the Spokane closing guide for the winterizing steps.
How long is the swim season in Spokane?
Spokane averages 70 days a year with normal highs of 80°F or better — right on the statewide median. The Washington season index ranks all 21 covered cities by the same metric.
How warm does pool water get in Spokane?
An unheated pool near Spokane typically peaks around 73°F in high summer and bottoms out near 31°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 Spokane hits the closing window
Data: NOAA 1991–2020 climate normals via Spokane Felts Field (5.3 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.