Pool season · Illinois
Aurora Pool Season: the Year on One Bar
Last updated: July 15, 2026 · dates · water temp
Aurora'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.
The bar compresses Aurora's whole pool year into one lane rope: gray floats for the off-season, hollow teal for the April 27–May 18 opening window, solid teal for swim weeks, hollow amber for the closing stretch that ends October 7. Wherever the today marker sits, the nearest color change is your next appointment.
The Aurora 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 7
The window opens September 27 once water leaves the algae zone; the model deadline is October 7, a week ahead of the October 23 freeze normal.
Estimated water temperature by month
This is Aurora'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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 25° | 24° | 33° | 44° | 56° | 66° | 73° | 74° | 70° | 59° | 46° | 34° |
The curve peaks near 74°F — comfortable-water months here usually involve a heater or a solar cover.
Email me when Aurora hits the closing window
Data: NOAA 1991–2020 climate normals via Aurora (1.5 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.