Pool season · Illinois
Peoria Pool Season: the Year on One Bar
Last updated: July 25, 2026 · dates · water temp
Peoria'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.
Peoria, IL — 101 swim days a yearThe bar compresses Peoria's whole pool year into one lane rope: gray floats for the off-season, hollow teal for the April 18–May 9 opening window, solid teal for swim weeks, hollow amber for the closing stretch that ends October 11. Wherever the today marker sits, the nearest color change is your next appointment.
The Peoria pool calendar
Opening — target April 25
Target April 25; the practical window runs April 18–May 9, and the 7-day mean crosses the 61°F threshold around May 9. Cold-water starts are the cheap ones.
Closing — deadline October 11
Hold the cover until October 1, then winterize by October 11, a week ahead of the October 23 freeze normal. Late and cold beats early and warm.
Estimated water temperature by month
This is Peoria'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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 27° | 27° | 36° | 48° | 59° | 69° | 76° | 76° | 72° | 61° | 48° | 36° |
The curve peaks near 76°F — comfortable-water months here usually involve a heater or a solar cover.
Every station tells its own story: compare this curve with Naperville's pool season and Rockford's — neighboring normals stations can shift the windows by a week or more. The full ranking lives on the Illinois season index.
Peoria pool season FAQ
When should I open my pool in Peoria, IL?
Open by April 25 — the model places Peoria's 61°F crossing about two weeks later, and every warm day you wait pushes the water toward the 65°F algae zone. The Peoria opening guide has the 12-step sequence.
When should I close my pool in Peoria?
Close by October 11: cool water keeps its winter chemistry, but freeze damage is the hard stop. The Peoria closing guide sequences the work backward from that date.
How long is the swim season in Peoria?
Peoria averages 101 days a year with normal highs of 80°F or better — about 10 days earlier than the Illinois median. The Illinois season index ranks all 18 covered cities by the same metric.
How warm does pool water get in Peoria?
An unheated pool near Peoria typically peaks around 76°F in high summer and bottoms out near 26°F in winter, never quite reaching the 78°F comfort line without a heater or solar cover. The month-by-month curve above shows the whole cycle; the methodology page explains the ±5°F error bars.
Email me when Peoria hits the closing window
Data: NOAA 1991–2020 climate normals via Peoria Gtr Peoria Airport (6.8 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.