PoolWindow

Pool season · Washington

Yakima Pool Season: the Year on One Bar

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

One bar, one year, one Yakima 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.

Cool blue pool in a short-season northern climateYakima, WA — 90 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

The bar compresses Yakima's whole pool year into one lane rope: gray floats for the off-season, hollow teal for the April 26–May 17 opening window, solid teal for swim weeks, hollow amber for the closing stretch that ends October 6. Wherever the today marker sits, the nearest color change is your next appointment.

The Yakima pool calendar

May 3open by
October 6close by
9080°F+ days
75°Fwater peak

Opening — target May 3

Target May 3; the practical window runs April 26–May 17, and the 7-day mean crosses the 61°F threshold around May 17. Cold-water starts are the cheap ones.

Full opening guide

Closing — deadline October 6

Hold the cover until September 26, then winterize by October 6, a week ahead of the October 23 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 Yakima water runs about 31°F at its winter floor and 75°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 Yakima'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.

20°30°40°50°60°70°80°90°JanFebMarAprMayJunJulAugSepOctNovDec65° algae zone58° swimmable startopen May 3close Oct 675°F peak31°F floor
Site-model seasonal water estimates for an unheated in-ground pool near Yakima #2 — ±5°F, see methodology.
JanFebMarAprMayJunJulAugSepOctNovDec
32°36°43°49°57°64°71°75°70°59°46°35°

The curve peaks near 75°F — comfortable-water months here usually involve a heater or a solar cover.

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

Yakima pool season FAQ

When should I open my pool in Yakima, WA?

Open by May 3 — the model places Yakima's 61°F crossing about two weeks later, and every warm day you wait pushes the water toward the 65°F algae zone. The Yakima opening guide has the 12-step sequence.

When should I close my pool in Yakima?

Close by October 6: cool water keeps its winter chemistry, but freeze damage is the hard stop. The Yakima closing guide sequences the work backward from that date.

How long is the swim season in Yakima?

Yakima averages 90 days a year with normal highs of 80°F or better — about 21 days earlier than the Washington median. The Washington season index ranks all 21 covered cities by the same metric.

How warm does pool water get in Yakima?

An unheated pool near Yakima typically peaks around 75°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.

Data: NOAA 1991–2020 climate normals via Yakima #2 (1.0 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.