PoolWindow

Pool season · Washington

Pasco Pool Season: the Year on One Bar

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

One bar, one year, one Pasco 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 Pasco's swim season; the hollow teal run before it (April 23 to May 14) is when to open; the hollow amber run after is when to close, with October 4 as the deadline; gray is the covered season. Today's marker shows where you stand in that cycle right now.

The Pasco pool calendar

April 30open by
October 4close by
10780°F+ days
76°Fwater peak

Opening — target April 30

Target April 30; the practical window runs April 23–May 14, and the 7-day mean crosses the 61°F threshold around May 14. Cold-water starts are the cheap ones.

Full opening guide

Closing — deadline October 4

Hold the cover until September 24, then winterize by October 4, a week ahead of the October 11 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 Pasco water runs about 34°F at its winter floor and 76°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 Pasco'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.

Site-model seasonal water estimates for an unheated in-ground pool near Pasco Tri Cities Airport — ±5°F, see methodology.
JanFebMarAprMayJunJulAugSepOctNovDec
34°36°42°50°57°65°72°75°69°58°46°37°

The curve peaks near 76°F — comfortable-water months here usually involve a heater or a solar cover.

Data: NOAA 1991–2020 climate normals via Pasco Tri Cities Airport (1.3 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.