Pool season · Oregon
Gresham Pool Season: the Year on One Bar
Last updated: July 15, 2026 · dates · water temp
This is the one-page view of Gresham's pool year: both model windows, the estimated water-temperature curve, and today's live position on the season bar. The detailed checklists live on the opening and closing guides; this page is the calendar you check between them.
Each dot on the bar is one week of Gresham'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 8–May 29), solid teal is swim season, and hollow amber is the closing window ending October 7. The black marker is today — its position against the colors is the entire executive summary.
The Gresham pool calendar
Opening — target May 15
Open by May 15 — a two-week head start on the May 29 crossing keeps startup chemistry small and beats the local service rush.
Closing — deadline October 7
Hold the cover until September 27, then winterize by October 7, a week ahead of the November 20 freeze normal. Late and cold beats early and warm.
Estimated water temperature by month
This is Gresham'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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 41° | 43° | 47° | 50° | 56° | 62° | 67° | 70° | 67° | 60° | 51° | 44° |
The curve peaks near 70°F — comfortable-water months here usually involve a heater or a solar cover.
Email me when Gresham hits the closing window
Data: NOAA 1991–2020 climate normals via Portland Troutdale Airport (3.7 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.