Best Times to See Mexico’s Butterfly Migration
The Monarch Butterfly Biosphere Reserve is a World Heritage Site containing most of the over-wintering sites of the eastern population of the monarch butterfly.
The 56,259 ha biosphere lies within rugged forested mountains about 100 km northwest of Mexico City. Every autumn, millions, perhaps a billion, butterflies from wide areas of North America return to the site and cluster on small areas of the forest reserve, coloring its trees orange and literally bending their branches under their collective weight.
In the spring, these butterflies begin an 8-month migration that takes them all the way to Eastern Canada and back, during which time four successive generations are born and die. How they find their way back to their overwintering site remains a mystery.
Every fall, millions of monarch butterflies migrate to central Mexico, where they winter in pine and fir trees in the state of Michoacán. Brilliant golden-orange butterflies covering the mountain forest and fluttering against the bright blue winter sky is a truly magical sight and something to plan a trip around.
To witness the yearly phenomenon, visit one of many sanctuaries within the Monarch Butterfly Biosphere Reserve between November (ideally mid-November, once more butterflies have settled in) and March.
At nearly all of the sanctuaries, you can hike, horseback ride or bike to see the butterflies in their wooded habitat. At some, you can even zip line back down the mountain.
The afternoon, when the air is warmer and the butterflies dance among the trees, is the perfect time of day to visit the sanctuaries.