Chicago's seasonal "Lights Out" program is now in effect through mid-June

Chicago’s seasonal Lights Out program has officially begun, marking a citywide effort to reduce nighttime light pollution during peak bird migration. From March 15 through June 15, buildings across the city are asked to switch off non-essential lights after 11pm and keep them off until sunrise.

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What is the Lights Out program?

At its core, it’s a conservation initiative. The program targets high-rise buildings, especially those over 40 stories or taller than 20 stories if they stand alone. Tenants and building managers are encouraged to turn off decorative lighting, dim interiors or close blinds late at night. Chicago was the first U.S. city to implement this program in 1999. Many U.S. cities have followed suit through a national Lights Out program.

What is the purpose of the Lights Out program?

For migratory birds, bright city lights can be deadly. Artificial light at night disrupts their navigation, causing them to circle illuminated buildings until they either collide with windows or collapse from exhaustion. Chicago sits along a major migration route, making it a critical point of intervention. The city estimates this program can save up to 10,000 birds each year.

When does the program run?

The spring phase runs from March 15 to June 15, aligning with one of the busiest migration periods. A similar effort typically returns in the fall.

How can Chicagoans participate in the Lights Out program?

Residents and building managers can:

• Turn off or dim lights after 11pm
• Close curtains or blinds to reduce light spill
• Use timers or motion sensors
• Opt for lower-intensity lighting
• Direct outdoor lighting downward to avoid “light trespass”

Even small changes, like switching from overhead lighting to a desk lamp, can make a difference.

Is it mandatory?

No. Participation is voluntary. The program relies on cooperation from building owners, businesses and residents. Education and awareness are key drivers, not enforcement.

What other cities are doing this?

The movement started in Toronto in 1991 with the Fatal Light Awareness Program (FLAP). Chicago followed in 1999 as the first U.S. city to adopt a similar approach. Today, more than 20 cities across North America—from Bend, OR and Atlanta, GA to New York, NY and Jacksonville, FL—run their own versions, often in partnership with conservation groups like the National Audubon Society.