Weather
Illinois Bird Migration Alert Friday Night 0ct 16: Millions Expected Overhead
Chicago, IL – Illinois residents could witness one of the season's major bird migration nights Friday, Oct. 16, as millions of birds are expected to travel across the United States after sunset, with
By Grant Holloway · 2026-10-16T15:13:33.564Z
Chicago, IL – Illinois residents could witness one of the season's major bird migration nights Friday, Oct. 16, as millions of birds are expected to travel across the United States after sunset, with much of Illinois positioned in a high intensity migration zone.
According to the Forest Preserve District of Will County, BirdCast, a migration forecasting project operated by the Cornell Lab of Ornithology, predicts approximately 436 million birds will be migrating across the country Friday night.
The forecast map places Illinois within a broad corridor of elevated migration activity stretching across the central United States and into portions of the Midwest and Southeast.
Peak Migration Expected After Sunset
Birds typically begin their nighttime migration approximately 30 to 45 minutes after sunset, with the greatest number in flight generally occurring two to three hours later, according to the Forest Preserve District.
For residents across Chicago, Will County and surrounding northern Illinois communities, that means significant migration activity could occur during the evening and overnight hours.
The 436 million figure represents the nationwide forecast, not the number expected to cross Illinois alone.
Residents Urged to Turn Off Unnecessary Lights
Wildlife officials are encouraging residents to switch off nonessential outdoor lighting during the migration.
Bright artificial lights can attract and disorient birds traveling at night, increasing their risk of colliding with windows and buildings.
Turning off unnecessary lights at homes, businesses and other properties can help reduce those hazards during periods of heavy migration.
The forecast highlights a major seasonal movement of birds, rather than a dangerous weather event or public safety emergency.
Residents interested in tracking migration intensity can view updated forecasts and migration maps at BirdCast.org.
With Illinois positioned along an active migration corridor, Friday night offers an opportunity to help protect migrating wildlife through a simple action: reducing unnecessary nighttime lighting.