PoolWindow

Pool season · Washington

Bellingham Pool Season: the Year on One Bar

Last updated: July 15, 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.

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 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

June 7open by
September 17close by
080°F+ days
65°Fwater peak

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.

Full opening guide

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.

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 Bellingham water runs about 40°F at its winter floor and 65°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 Bellingham'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 Bellingham 3 SSW — ±5°F, see methodology.
JanFebMarAprMayJunJulAugSepOctNovDec
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.

Data: NOAA 1991–2020 climate normals via Bellingham 3 SSW (3.2 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.