Real-Time Migration Maps & Forecasts

Nightly migration forecasts, radar loops, and links to every state’s Lights Out page.

Watch bird migration unfold in real time.

This flow map uses weather radar to reveal where birds are flying, how many are in the air, and the speed and direction of their movements. Hover over radar sites for flight details, or zoom in to explore more closely.

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Bird density (absolute)
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Radar site status
data collected
radar not operational
NEXRAD animation (Source: U. of Wisconsin)

Learn more about light pollution

Bird Migration Forecast (Next 3 Nights)

Totals shown in million birds.

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.
Migratory flow animation
50% of migrants pass on just 10% of seasonal nights

How to use “Lights out alert forecast”

  • The alert maps show relative migration intensity. This differs from migration intensity maps, which show absolute intensity.
  • Context matters: intense migration in one region can be low in another (e.g., south Texas vs. Colorado).
  • Using relative intensity enables alerts across the U.S. tuned to local conditions.
  • Alert levels: no alert, low, medium, high.
  • High alert (red) nights are ~10% of the season (~9 nights) but account for ~51% of total movement.