Migration Forecasts
Nightly migration forecasts, radar loops, and links to every state’s Lights Out page.
Updated daily
Lights Out guidance
If your city is within its peak migration window, dim or turn off non‑essential outdoor lighting from 11 pm–6 am and close shades to reduce skyglow.
Why “Lights Out” helps
- Reduces collision risk by lowering skyglow and drawing fewer birds into brightly lit urban cores.
- Conserves energy & saves money by dimming or switching off non‑essential lighting during peak migration.
- Protects habitat quality by keeping nights darker for resting birds near important stopover hotspots.
How to use “Lights out alert forecast”
- The alert maps show relative migration intensity. This is an important distinction from the migration intensity map, which shows absolute migration intensity.
- Why is this important? Intense migration in one area could be low intensity in another. For instance, south Texas typically sees greater migration intensity than Colorado.
- Using relative intensity, we can make alerts across the entire U.S. and tune the alerts to local conditions.
- The alert maps have four levels: no alert, low, medium, and high. These alert levels correspond to the colored boxes above.
- High alert (red) nights see a tremendous amount of migration activity. These events account for only 10% of the nights in a season (~9 nights), but represent about 51% of the total seasonal movement. More often than not, the maps will be gray—meaning no alert has been issued. Yet, if you can turn off your lights, regardless of the alert status, even better.