When, Where and How to Watch
Fall Monarch Migration

(Slideshow Overview)

Migrating Monarchs
As monarchs travel to Mexico through your hometown, what signs of migration might you see? Watch for monarchs:

  • nectaring from flowers
  • flying in directional flight
  • roosting in clusters overnight.

Nectaring Monarchs
One of the surest ways to see migrating monarchs is to plant flowers to attract them. Monarchs may drop from the sky for the food they need during fall migration.

"We planted our garden in the middle of a city and they found us!" a teacher wrote from Minnesota.

Flying Monarchs
Go outside, lie down on your back, and simply look up at the sky! You'll know a migrating monarch if you see one that seems to be flying with a purpose, and traveling in one direction. This is called "directional flight." You may see only one butterfly, but it's a thrill when you see that it's traveling toward Mexico.

"Every monarch was traveling in the same direction, as if they were following a road in the sky!" wrote an observer from New York.

Roosting Monarchs
Monarch butterflies only migrate during the day. At night they cluster together in overnight roosts. Some roosts last for only one night. Others last for two weeks or more. A roost may have a handful of butterflies or far too many to count.

"We had 200 to 300 monarchs in the large trees in our schoolyard. We're only a block from Lake Ontario so it was a good place to rest before heading onward!" wrote students from Ontario.

When to Watch
This roost map shows when peak migration typically occurs. The timing is similar from one year to the next. The best time for you to see migrating monarchs is when people in your state or province are reporting roosts.

Where to Watch
There are two populations of migratory monarchs in North America. This map shows their primary breeding ranges. The population that migrates to Mexico crosses the area shown in red. You can see migration anywhere in that region. The number of monarchs you see will vary depending on habitat, geography, food, wind and weather.

How to Watch
In order for your observations to be useful, record how many monarchs you see and how much time you spend watching. That way, your observations can be compared from one time to the next and from one place to the next.

Help Track Fall Migration
Flying, resting and refueling, monarchs migrate to Mexico every fall from August to November. Report your sightings! Help shed light on the many mysteries of monarch migration.