Pool season · Illinois
Elgin Pool Season: the Year on One Bar
Last updated: July 15, 2026 · dates · water temp
This is the one-page view of Elgin'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.
The bar compresses Elgin's whole pool year into one lane rope: gray floats for the off-season, hollow teal for the April 30–May 21 opening window, solid teal for swim weeks, hollow amber for the closing stretch that ends October 4. Wherever the today marker sits, the nearest color change is your next appointment.
The Elgin pool calendar
Opening — target May 7
Open by May 7 — a two-week head start on the May 21 crossing keeps startup chemistry small and beats the local service rush.
Closing — deadline October 4
The window opens September 24 once water leaves the algae zone; the model deadline is October 4, a week ahead of the October 18 freeze normal.
Estimated water temperature by month
This is Elgin'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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 24° | 23° | 31° | 43° | 54° | 65° | 73° | 73° | 69° | 58° | 45° | 33° |
The curve peaks near 74°F — comfortable-water months here usually involve a heater or a solar cover.
Email me when Elgin hits the closing window
Data: NOAA 1991–2020 climate normals via Elgin (2.5 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.