Monarch Migration 2026: When They Reach Your State

The autumn southbound migration crosses the United States as a wave. On this site's own windows it peaks in the northern tier states from late August, works down through the Midwest and the mid Atlantic through September, and reaches the Gulf states and Texas in October. There is no single national date, which is why every state has its own page. The northbound spring wave runs the other way from March, but it is not one arrival: USFWS states that "As temperatures warm at the overwintering sites in the spring, monarchs begin to breed and lay eggs on milkweed throughout their spring journey."

Not under United States law, and this is stated wrongly almost everywhere. US Fish and Wildlife Service proposed listing the monarch as threatened on December 12, 2024, with a section 4(d) rule and proposed critical habitat. As of Aug 24, 2026 no final rule has been published and the monarch has no federal listing. The monarch is very widely described online as endangered. Under United States law it is not. The International Union for Conservation of Nature, which is a different body with no legal force in the US, assessed the migratory monarch separately, and its assessment has itself been revised. Those two things get merged constantly. This site states the federal position and names it as the federal position.

Volunteers report monarch eggs, larvae, adults and autumn roosts as they see them, and the reports are plotted on a live map. For the question of where the leading edge of the migration is this week, in this particular year, it is the best resource in North America and it has been for decades. It is a map of what has been reported, not a statement of what to expect. It has no per-state page and no typical window, so it cannot answer "when should I expect them in Ohio" before the sightings exist. It also does not cover the planting half of the question. This site is the other half: a typical window per state, derived from the open observation record, and the milkweed and nectar answer next to it. When the season is live, go and look at their map. Their data is published under a NonCommercial Creative Commons licence, so this site links their map rather than building on their sightings.

Two corrections, and both move the answer. Records are restricted to observations a human annotated as ADULT, because larvae and eggs are photographed heavily and peak weeks earlier: nationally there are 371,630 monarch records in the covered states and 241,416 of them are annotated adults. And counts are divided by all research grade observations in the same state and month, which removes the effect of how many people happened to be outdoors. The late April spike several southeastern states show in a raw count is the City Nature Challenge, not butterflies.

No. In all 44 covered states the last regular monarch sightings fall AFTER the median first freeze from NOAA normals, by a median of 22 days. A first freeze in the NOAA sense is a light radiational frost at 32 degrees, not the hard freeze that ends a season. The practical consequence is that cutting a garden back at the first frost takes nectar away from butterflies that are still passing through.

Two places, and which one depends on which side of the Rockies you are on. USFWS states that "The Rocky Mountains generally divide these two populations, limiting their contact." Eastern monarchs, meaning most of the country, fly to central Mexico: "In the fall, they may fly more than 2,000 miles (3,000 km) to reach overwintering sites in Mexico." Western monarchs go to the California coast: "The western population overwinters in hundreds of groves (clusters of trees) along the California coast and into northern Baja California, Mexico." On this site 4 states are tagged western and 3 sit on the divide and are tagged as neither, because USFWS also notes the two populations are not completely isolated.

Whatever is native where you are, and every state page here lists the milkweeds actually recorded in that state. Xerces states: "The Xerces Society recommends planting milkweed species that are locally native and for which regionally-sourced seeds and plants are available." The one to avoid is the one garden centres stock: Xerces states "we do not recommend planting tropical milkweed" because "tropical milkweed that remains evergreen through winter allows for OE levels to build up on the plant over time" and because "The presence of tropical milkweed in winter may cause monarchs to breed rather than migrating and overwintering."

In autumn, from about your first freeze. Xerces states: "In most regions, fall planting is a good approach because the seeds' exposure to cold, moist conditions during winter and spring will help stimulate germination." Milkweed seed germinates far better after a cold moist winter, so the sowing date is a frost date, and each state page here derives it from that state's median first freeze rather than from a national rule of thumb.

The Xerces Society coordinates the count. The Western Monarch Count website is administered by the Xerces Society for Invertebrate Conservation on behalf of the Western Monarch Count. The most recent figures it has published are about 12,260 monarchs across 249 sites in the 2025 mid season count, the one usually called the thanksgiving count, and 6,464 monarchs across 193 sites in the 2025 to 2026 late season count, surveys ending january 11, 2026. The percentage decline figures that circulate for the western population against a 1980s baseline do not appear on the Western Monarch Count’s own pages.

44 states. Alaska has no research grade iNaturalist records of Danaus plexippus at all, so there is no curve to derive a window from. Monarchs are not part of the Alaskan fauna in any regular way. Hawaii has a well established monarch population and thousands of records, and it does not migrate. The butterflies breed year round on introduced milkweeds, so an arrival window and a departure window would describe an event that does not happen there. The species is present; the migration is not. These states fall below the floor of 300 research grade records annotated as adult monarchs. Below that the weekly curve is dominated by a handful of individual observers and the thresholds move by weeks when a single record moves. Monarchs occur in all of them; the observation record is too thin to date them. The states without a page are named on this page with the reason.