The U.S. Department of the Interior recently posted that the annual monarch butterfly migration is about to begin.
The monarch migration is about to begin.
Along the way, they depend on native flowering plants to rest and refuel. Planting native wildflowers and milkweed in your yard or in your community is one simple way to help these remarkable travelers complete their journey. pic.twitter.com/yyEFnmPgCJ
— US Department of the Interior (@Interior) August 11, 2026
Eastern North American monarchs, the population relevant to Texas, undertake a multi-generational migration each year. In the fall, the final generation of the season flies south from breeding grounds in the northern United States and Canada to overwintering sites in the mountains of central Mexico, a journey that can cover up to 3,000 miles for some individuals.
Timing of the Fall Migration
According to the Monarch Joint Venture, eastern monarchs begin migrating south in late summer. In northern areas, movement often starts in early August to late September. Farther south, successful migration typically occurs from early September to late October.
Monarch Watch data indicate peak abundance shifts by latitude. Around latitude 33 degrees, which includes parts of North Texas such as the Denton area, the midpoint falls near October 7, with peak numbers generally expected from late September through mid-October.
Texas Parks and Wildlife Department states that monarchs enter the central Texas flyway during the last days of September. Most pass through into Mexico by early November. A coastal flyway sees activity roughly from the third week of October to mid-November.
The migration ends when the butterflies reach oyamel fir forests in central Mexico, typically arriving around early November.
What North Texans Can Expect
North Texas sits within the central flyway, a roughly 300-mile-wide corridor stretching from Wichita Falls toward Eagle Pass. Texas Parks and Wildlife notes that all eastern monarchs must cross Texas, where the migration path narrows and concentrates.
Residents may notice increased numbers of the distinctive orange-and-black butterflies resting or nectaring on flowers, especially on warm, sunny days following cold fronts that push them southward. Sightings can range from individual insects to larger groups, though large roosts or dense clouds are more common farther south in the Hill Country or coastal areas.
The event is annual and occurs twice yearly: the southbound fall migration and the northbound spring return, which begins in March as overwintering adults leave Mexico.
How People Can Help
The Department of the Interior recommended planting native wildflowers and milkweed in yards or communities to provide resting and refueling sites.
Milkweed serves as the sole host plant for monarch larvae. Native species support breeding earlier in the season. During fall migration, adult monarchs enter reproductive diapause and prioritize nectar from flowering plants to build energy reserves for the long flight.
Avoiding pesticides and insecticides in gardens helps protect both larvae and adults. Creating continuous habitat corridors of native plants along migration routes supports the insects without requiring specialized equipment or large land holdings. Small plantings in residential yards contribute cumulatively.
Observers can report sightings to community science programs such as Journey North to aid tracking efforts.
Population Context
The most recent overwintering census in Mexico, released in March 2026 by the World Wildlife Fund and Mexico’s National Commission of Protected Natural Areas, recorded monarchs occupying 2.93 hectares in December 2025.
That figure represented a 64% increase from the previous year and slightly exceeded the 10-year average of 2.81 hectares, though it remains well below historic levels from the 1990s.
The fall migration forms a key stage in the species’ annual cycle. Successful passage through Texas and adequate fuel along the route influence how many butterflies reach the overwintering sites.
