The monarch's 3,000-mile journey
The monarch's 3,000-mile journey is about to begin
- Sun, Sep 6 2026 at 11:54 AM
Mark M,
The monarch butterfly fluttering through your neighborhood this fall could be headed thousands of miles south -- on a journey its parents never made.
Over the coming weeks, flashes of orange will move south across backyards, fields and forests, on a journey that stretches across an entire continent. For an insect no heavier than a paperclip, the scale of the journey is almost hard to believe.
Let's follow the monarch on its extraordinary migration and take a look at what these butterflies need to survive the journey.
Most monarch butterflies live only a few weeks. But as summer draws to a close, a special "super generation" emerges that can live for months -- up to eight times longer than earlier generations.1
That extra time is essential, as this is the generation that makes the long journey south. Eastern monarchs can travel up to 3,000 miles to wintering grounds in central Mexico, while western monarchs migrate toward the California coast and northern Baja California.2
Even more astonishing, these butterflies have never made the trip before. The monarchs heading south this fall are several generations removed from those that began the journey north in the spring.
So how do they know where to go?
Scientists know monarchs use cues including the sun, changing day length and temperature to guide them. But exactly how they find wintering grounds they've never seen remains one of the remarkable mysteries of monarch migration.3
Fall monarchs are built for life on the move. Research has found that they grow larger wings and devote more of their body mass to the thorax -- physical differences that help prepare them for migration.4
But monarchs don't rely on wing power alone. They can ride rising currents of warm air, sometimes soaring as high as a mile above the ground. On a good day, a migrating monarch can cover around 50 miles.5
A journey of thousands of miles still takes an enormous amount of energy. Monarchs stop along the way to sip nectar from late-summer and fall wildflowers, building up the fat reserves to fuel their flight and sustain them through winter.6 That makes even small patches of flowering habitat -- from backyard gardens to roadsides to county parks -- essential stopovers on the long journey south.
Habitat loss, disappearing food sources and pesticides are making the monarch's remarkable migration even harder.
Milkweed is the only plant monarch caterpillars can eat. But glyphosate, the most widely used herbicide in the United States, can wipe it out, and research has linked glyphosate-driven milkweed loss to monarch declines.7
There are signs of hope, but monarch populations remain in trouble: Eastern monarchs nearly doubled from the previous year, but remain far below historic numbers. Western monarchs are still in especially dire shape.8
For generations, monarchs have found their way across North America. But even these remarkable travelers can't overcome disappearing habitat, dwindling milkweed and pesticides like glyphosate on their own. By protecting the landscapes they depend on and reducing pesticide threats, we can help ensure that one of nature's greatest migrations continues for generations to come.
Thank you,
Lisa Frank
Executive Director
1. Mara Koenig, "The phenomenal monarch migration," U.S. Fish & Wildlife Service.
2. Farmers' Almanac Staff, "The Great Monarch Butterfly Migration Is About To Begin," Farmers' Almanac, August 13, 2026.
3. Farmers' Almanac Staff, "The Great Monarch Butterfly Migration Is About To Begin," Farmers' Almanac, August 13, 2026.
4. Ayse Tenger-Trolander et al., "Seasonal plasticity in morphology and metabolism differs between migratory North American and resident Costa Rican monarch butterflies," Ecology and Evolution, February 22, 2023.
5. Mara Koenig, "The phenomenal monarch migration," U.S. Fish & Wildlife Service.
6. Farmers' Almanac Staff, "The Great Monarch Butterfly Migration Is About To Begin," Farmers' Almanac, August 13, 2026.
7. Steve Blackledge, "For struggling butterflies, if it's not one pesticide, it's another," Environment America, July 11, 2024.
8. "Good news and bad news for monarch butterflies -- and what you can do," Environment America, March 27, 2025.
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