Pool season · Iowa
Cedar Rapids Pool Season: the Year on One Bar
Last updated: July 15, 2026 · dates · water temp
This is the one-page view of Cedar Rapids'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 Cedar Rapids'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 27–May 18), solid teal is swim season, and hollow amber is the closing window ending October 2. The black marker is today — its position against the colors is the entire executive summary.
The Cedar Rapids pool calendar
Opening — target May 4
Target May 4; the practical window runs April 27–May 18, and the 7-day mean crosses the 61°F threshold around May 18. Cold-water starts are the cheap ones.
Closing — deadline October 2
The window opens September 22 once water leaves the algae zone; the model deadline is October 2, a week ahead of the October 11 freeze normal.
Estimated water temperature by month
This is Cedar Rapids'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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 21° | 21° | 31° | 44° | 55° | 66° | 72° | 72° | 68° | 57° | 43° | 30° |
The curve peaks near 73°F — comfortable-water months here usually involve a heater or a solar cover.
Email me when Cedar Rapids hits the closing window
Data: NOAA 1991–2020 climate normals via Cedar Rapids Municipal Airport (6.1 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.