Pool season · Washington
Bellingham Pool Season: the Year on One Bar
Last updated: July 25, 2026 · dates · water temp
One bar, one year, one Bellingham pool. The season bar below draws everything the model knows — opening window, prime season, closing window — against today's date, with the working details one click away on the opening and closing pages.
Bellingham, WA — 0 swim days a yearReading it takes ten seconds: 52 dots, one per week. Solid teal is Bellingham's swim season; the hollow teal run before it (May 31 to June 21) is when to open; the hollow amber run after is when to close, with September 17 as the deadline; gray is the covered season. Today's marker shows where you stand in that cycle right now.
The Bellingham pool calendar
Opening — target June 7
Target June 7; the practical window runs May 31–June 21, and the 7-day mean crosses the 61°F threshold around June 21. Cold-water starts are the cheap ones.
Closing — deadline September 17
The window opens September 7 once water leaves the algae zone; the model deadline is September 17, a week ahead of the November 2 freeze normal.
Estimated water temperature by month
Monthly averages of the site's water model run on Bellingham'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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 41° | 42° | 44° | 48° | 53° | 59° | 63° | 65° | 62° | 56° | 48° | 43° |
The curve peaks near 65°F — comfortable-water months here usually involve a heater or a solar cover.
Every station tells its own story: compare this curve with Bellevue's pool season and Bremerton's — neighboring normals stations can shift the windows by a week or more. The full ranking lives on the Washington season index.
Bellingham pool season FAQ
When should I open my pool in Bellingham, WA?
Target June 7. That date backs off two weeks from the day Bellingham's 7-day mean temperature reaches 61°F, so you start up in cold, algae-resistant water. Work the full checklist in the Bellingham opening guide.
When should I close my pool in Bellingham?
The closing deadline is September 17 — late enough that the water has cooled out of the algae zone, early enough to beat Bellingham's first-freeze normal by about a week. See the Bellingham closing guide for the winterizing steps.
How long is the swim season in Bellingham?
Bellingham averages 0 days a year with normal highs of 80°F or better — about 14 days later than the Washington median. The Washington season index ranks all 21 covered cities by the same metric.
How warm does pool water get in Bellingham?
An unheated pool near Bellingham typically peaks around 65°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.
Email me when Bellingham hits the closing window
Data: NOAA 1991–2020 climate normals via Bellingham 3 SSW (3.2 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.