Families heading to Centennial Beach on Thursday, July 16, found the gates locked. Wildfire smoke from Canada and Minnesota blanketed the Naperville area, pushing air quality into "very unhealthy" territory and forcing the Naperville Park District to close both the beach and the Paddleboat Quarry for the day.
The closure affects two of downtown Naperville's busiest summer draws along the Riverwalk, on a day with a forecast high of 93 degrees.
What happened
The Park District posted its closure notice Thursday morning, citing "extremely poor air quality." The district did not specify an AQI threshold for the decision, and its public weather cancellation guidelines page does not list a specific trigger number.
By 9 a.m. Thursday, the AQI in the Chicago area had reached 267 on a 500-point scale, according to the Chicago Tribune citing AirNow data. That figure placed the region in the "very unhealthy" category, meaning health risks extend to everyone outdoors, not just sensitive groups. Aurora, which borders Naperville, registered in the same category.
At that hour, Chicago ranked as the fourth most-polluted major city in the world, behind Detroit, Toronto and Minneapolis, according to Swiss air quality company IQAir.
Health guidance
The Illinois Environmental Protection Agency recommended that residents limit physical activity outside when the AQI exceeds 150 and close windows and doors indoors. AirNow guidance goes further for the "very unhealthy" range: people with heart or lung disease, older adults, children and teens should avoid outdoor physical activity entirely, and everyone else should skip strenuous exercise outside.
The main pollutant driving Thursday's readings is PM2.5, fine particulate matter small enough to settle deep in the lungs and cross into the bloodstream. Common symptoms include burning eyes and nose irritation.
What's next
The Park District has not announced whether Centennial Beach or the Paddleboat Quarry will reopen Friday, July 17. Residents can check napervilleparks.org or the district's social media accounts for updates. The district's weather cancellation guidelines page was displaying the closure alert as of Thursday afternoon.
The AQI figure of 267 was measured as of 9 a.m. and may have shifted during the day. The Chicago Tribune noted conditions were being updated throughout Thursday.
City Hall week ahead
- Tuesday, July 21 — Chat with the Chief, 10:30 a.m. to noon, Arwa Yemeni Coffee, 3124 S. Route 59. Naperville Police Chief Jason Arres takes questions from residents on public safety.
- Through Thursday, July 30 — Naperville Park District seeks public input on seven proposed 2027 capital improvement projects, including new ballfields at Wolf's Crossing Community Park. Submit feedback at napervilleparks.org/parkandfacilityimprovements.
- Saturday, August 8 — Rescheduled community fireworks show, Frontier Sports Complex.
