Bird migration tonight
Is tonight a good night for bird migration activity in my area?
Most songbirds migrate at night, and they move in pulses — a front passes, winds turn favorable, and suddenly millions of birds are aloft where the previous night had thousands. Spring and fall each bring a couple of months of these waves.
This tool estimates tonight's migration intensity for your city from season and weather conditions, so birders know when tomorrow morning's patch will be busy — and everyone else knows why the radar looked strange overnight.
Big migration nights are also when window collisions and light pollution do the most harm: on heavy nights, turning off non-essential exterior lighting genuinely helps birds pass safely.
Check a major city
How it works
Billions of birds migrate across North America each spring and fall, mostly at night. This forecast uses seasonal migration calendars calibrated to your latitude — migration peaks earlier in the south and later in the north. Wind speed and precipitation also matter: calm, clear nights see the highest migration activity, while rain and strong headwinds ground birds. The forecast is a seasonal model, not live radar, so treat it as a general guide. For live radar-based migration data, check the BirdCast Migration Dashboard from Cornell Lab of Ornithology.