Pool season · Colorado
Grand Junction Pool Season: the Year on One Bar
Last updated: July 15, 2026 · dates · water temp
This is the one-page view of Grand Junction'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 Grand Junction's typical year, colored by what the model says that week is for: gray weeks are off-season, hollow teal marks the opening window (April 19–May 10), solid teal is swim season, and hollow amber is the closing window ending October 12. The black marker is today — its position against the colors is the entire executive summary.
The Grand Junction pool calendar
Opening — target April 26
Target April 26; the practical window runs April 19–May 10, and the 7-day mean crosses the 61°F threshold around May 10. Cold-water starts are the cheap ones.
Closing — deadline October 12
The window opens October 2 once water leaves the algae zone; the model deadline is October 12, a week ahead of the October 23 freeze normal.
Estimated water temperature by month
Monthly averages of the site's water model run on Grand Junction'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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 28° | 32° | 42° | 51° | 59° | 70° | 78° | 79° | 73° | 62° | 47° | 35° |
Warmest water typically July–August (peaking near 80°F); heaters and covers shift any month up.
Email me when Grand Junction hits the closing window
Data: NOAA 1991–2020 climate normals via Grand Junction Wfo (3.2 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.