Pool season · Washington
Bellevue Pool Season: the Year on One Bar
Last updated: July 15, 2026 · dates · water temp
Bellevue'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.
Each dot on the bar is one week of Bellevue's typical year, colored by what the model says that week is for: gray weeks are off-season, hollow teal marks the opening window (May 17–June 7), solid teal is swim season, and hollow amber is the closing window ending October 1. The black marker is today — its position against the colors is the entire executive summary.
The Bellevue pool calendar
Opening — target May 24
Open by May 24 — a two-week head start on the June 7 crossing keeps startup chemistry small and beats the local service rush.
Closing — deadline October 1
The window opens September 21 once water leaves the algae zone; the model deadline is October 1, a week ahead of the November 16 freeze normal.
Estimated water temperature by month
This is Bellevue'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.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 42° | 43° | 45° | 49° | 55° | 60° | 65° | 68° | 65° | 58° | 50° | 43° |
The curve peaks near 68°F — comfortable-water months here usually involve a heater or a solar cover.
Email me when Bellevue hits the closing window
Data: NOAA 1991–2020 climate normals via Renton Municipal Airport (7.6 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.