Nearing Northern Limits

June 7, 2018 by Elizabeth Howard

Traveling in pursuit of milkweed, monarchs are nearing milkweed's northern limits - and the end of spring migration.

This monarch in Ottawa, Ontario is about 250 miles from the northern limit of the monarch’s breeding range. Image by Gordon Johnston

Almost There…

For 3 months, monarchs have been traveling in pursuit of milkweed. This map shows how far north milkweed grows — and the northern extent of migration. Monarchs don’t want to go where milkweed doesn’t grow!

  • In the central region, the northernmost monarchs have already reached milkweed’s northern limit in southern Manitoba.
  • In the east, monarchs will travel another 300 miles into Canada’s Maritime provinces and Quebec.

Generation Two

Females are laying eggs of the 2nd generation now. These monarchs will be the grandchildren of butterflies that overwintered in Mexico.

Counting Generations

Monarch generations are continuing to cycle. It takes about one month for each to develop. Over the summer, three generations will be produced in the north.

June: grandchildren

July: great-grandchildren

August: great-great-grandchildren—the generation that migrates to Mexico.

Report Your First

No matter when you see your first monarch, we want to know about it. Your sighting is important even if other people have already reported from your region.

Monarchs in June