How to Spot Migrating Monarch Butterflies in Indiana

Every fall, an incredible migration occurs through the state of Indiana, where millions of tiny monarch butterflies fly on their way to overwintering grounds in Mexico, only to return in the spring to breed and lay their eggs.

What Are Monarch Butterflies? 

Monarch butterflies (Danaus plexippus) are a striking orange, black, and white species of butterfly native to North America. Best known for their annual long-distance migration, these butterflies fly thousands of miles to Mexico and California every year. Unfortunately, monarchs have been in the news recently for their significant declines in the past few decades. 

What Is Monarch Migration? 

Migration refers to the seasonal, long-distance movement of a species, driven by the availability of resources like food and water, or by environmental changes such as temperature shifts that make the habitat temporarily unsuitable. Monarchs undergo the longest migration of any butterfly, traveling up to three thousand miles to their wintering grounds in Mexico and California. 

The distances monarchs travel are comparable to those in much larger vertebrate animals like mammals and birds, yet monarchs weigh less than one gram with a wingspan shorter than four inches. Unlike mammals and birds, monarch butterflies require multiple generations to complete their migration cycle, making it more complex.

Why Do Monarch Butterflies Migrate? 

Monarch butterflies cannot tolerate the cold temperatures that cover much of Canada and the United States during the winter months. Therefore, they seek shelter in roosting spots along the Californian coast in small groves of trees and in mountain forests in Mexico. When day length becomes shorter and temperatures drop, the monarch begins its fall migration southward. 

How Does Migration Work?

Because monarch migration is cyclical and has no specific starting point, it is easiest to understand by beginning with the fall migratory movements. The monarchs emerging at this time from their pupae are different biologically and behaviorally from those that have emerged earlier in the summer. Triggered by shorter days and cooler temperatures, these butterflies emerge around late August for areas in the north until November in areas farther south. These are the butterflies that will migrate thousands of miles south to Mexico or California. 

Monarchs can travel over 100 miles in just one day and at elevations up to 1,200 feet high under the right conditions. One butterfly was found 265 miles away from a release site the following day! Along their migration route, they stop to forage on the nectar of different flowers in addition to surviving on fat stored in their abdomen. They make sure to conserve precious energy by using air currents to glide, minimizing the costs associated with flying. Monarchs likely use the Earth’s magnetic fields to navigate, yet it is unknown how they locate the exact area that their great-great-grandparents used, as they had never been there before themselves. 

They arrive in California or Mexico and spend the winter months in large clusters, sometimes with tens of thousands of monarchs in a single tree where they mate. When the second week of March arrives, they begin to fly north in search of milkweed plants to lay their eggs before they die, but not as far north as their original habitat. These butterflies live for a total of eight to nine months.

These eggs hatch after three to four days, and the first spring caterpillars emerge. Ten to fourteen days later, these caterpillars enter chrysalis, and after another ten to fourteen days, they metamorphose into the adults that continue the journey to recolonize their parents’ original habitat. These butterflies live much shorter lives—only two to six weeks—and continue to reproduce throughout the summer in breeding areas.

Each female born throughout the summer can lay hundreds of eggs, and a total of three to four generations are born throughout the season. As a result, millions of monarch butterflies populate the US and southern Canada during this time. As fall returns, cooler temperatures and shorter days trigger the emergence of the migratory generation of monarch butterflies, and the cycle begins again.

When to See Monarch Butterflies in Indiana

Monarchs return from migration in spring as early as April, but as Indiana is farther north, they often don’t reach the state until May or later. Ashley Hansen, who has researched monarch butterflies, says, “It can fluctuate from year to year. You should start seeing them between late March and the end of July.”

Wendy Caldwell, Executive Director at the Monarch Joint Venture, states, “they typically arrive between mid-May and early June, and are present throughout the summer.”

Monarchs can be seen in Indiana all summer long, until they begin their migration south from the end of August through November. Hansen adds, “In my personal experience, you are more likely to encounter one during late morning, early afternoon – the hottest parts of the day.” 

Although monarchs are in Indiana throughout the summer, the best times to see them are during the fall migration when millions of butterflies pass through the state on their way to their southern wintering grounds. In Northeast Indiana, peak butterfly season is in mid-September, where they can be seen foraging on nectar from various flowering plants.

Where to See Monarch Butterflies in Indiana

Monarchs can be seen throughout Indiana, as the state provides important breeding and migratory habitat for the butterflies. They can be seen anywhere there is either milkweed for laying eggs or flowers for food for adults. 

Female monarchs lay their eggs exclusively on milkweed plants, for which there are over 100 species in North America, and the caterpillars only eat milkweed leaves. Ecologist Lee Walston says, “They’re attracted to native milkweed plant species, which are the host plants for their caterpillars. So anywhere where there are good stands of milkweed will be good locations to see monarchs.”

Adult monarchs can also be seen outside of milkweed as they forage on a wide range of flowers for nectar. Hansen says, “You are most likely to see them in spaces with an abundance of nectaring sources, preferably a variety, and/or with good roosting habitat for them if it’s towards the start or end of the day.” 

Caldwell explains that “Throughout the summer, find monarchs in gardens, roadsides, and open fields, wherever there is milkweed and other wildflowers!” She adds that “Starting around mid-August, you may see them start to roost in large groups in trees when they’re beginning their migration to Mexico.”

Some hotspots to see monarch butterflies in Indiana include the Little River Wetlands and Eagle Marsh, located southwest of downtown Fort Wayne, as well as multiple monarch waystations in the Indiana Dunes.

Hansen also recommends using the community science program Journey North’s resource on monarch locations. Reviewing recent sightings could help you or others decide where to look next.

Why Monarch Butterflies Are Under Threat

Although monarch populations have experienced significant declines over the past few decades, the eastern monarch population saw a notable rebound in early 2025, nearly doubling from the previous year. However, numbers remain below long-term averages. The species’ struggles are attributable to the loss of milkweed for larval monarchs and important nectar sources for adults, due to the development of land, largely for agriculture. The U.S. Fish and Wildlife Service has proposed listing monarch butterflies as a threatened species under the Endangered Species Act.

One way anyone can help monarchs in Indiana is by planting milkweed for caterpillars and native plants that produce nectar for foraging adults. Walston says, “One of the best ways to conserve monarchs is to plant milkweed. Common milkweed is a very easy-to-grow plant that can establish in a variety of conditions.”