Pool season · Washington
Kennewick Pool Season: the Year on One Bar
Last updated: July 25, 2026 · dates · water temp
Kennewick'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.
Kennewick, WA — 101 swim days a yearThe bar compresses Kennewick's whole pool year into one lane rope: gray floats for the off-season, hollow teal for the April 19–May 10 opening window, solid teal for swim weeks, hollow amber for the closing stretch that ends October 11. Wherever the today marker sits, the nearest color change is your next appointment.
The Kennewick pool calendar
Opening — target April 26
Open by April 26 — a two-week head start on the May 10 crossing keeps startup chemistry small and beats the local service rush.
Closing — deadline October 11
The window opens October 1 once water leaves the algae zone; the model deadline is October 11, a week ahead of the October 30 freeze normal.
Estimated water temperature by month
Monthly averages of the site's water model run on Kennewick'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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 35° | 37° | 43° | 51° | 59° | 66° | 74° | 78° | 71° | 61° | 48° | 38° |
Warmest water typically August–August (peaking near 78°F); heaters and covers shift any month up.
Every station tells its own story: compare this curve with Federal Way's pool season and Kent's — neighboring normals stations can shift the windows by a week or more. The full ranking lives on the Washington season index.
Kennewick pool season FAQ
When should I open my pool in Kennewick, WA?
Open by April 26 — the model places Kennewick's 61°F crossing about two weeks later, and every warm day you wait pushes the water toward the 65°F algae zone. The Kennewick opening guide has the 12-step sequence.
When should I close my pool in Kennewick?
Close by October 11: cool water keeps its winter chemistry, but freeze damage is the hard stop. The Kennewick closing guide sequences the work backward from that date.
How long is the swim season in Kennewick?
Kennewick averages 101 days a year with normal highs of 80°F or better — about 28 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 Kennewick?
An unheated pool near Kennewick typically peaks around 78°F in high summer and bottoms out near 35°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 Kennewick hits the closing window
Data: NOAA 1991–2020 climate normals via Kennewick (3.5 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.