Where monarchs live

Monarchs breed across most of the United States and southern Canada and spend the winter in two places: the eastern population in the mountains of central Mexico, and the much smaller western population in groves along the California coast.¹² Some monarchs in Florida, along the Gulf Coast and in southern California don’t migrate at all,² and in a few places they are rarely seen: the Puget Sound region is one, and for Alaska we could find no verified record at all.³⁴ Where you live decides which of these is true for your yard, and this page explains how our city finder decides.

Two populations, split by the Rocky Mountains

Monarch Joint Venture: “Monarchs that spend the summer breeding season in eastern North America (including states and provinces east of the Rocky Mountains: central and eastern Canada, midwestern and eastern United States) migrate to the Transvolcanic mountains of central Mexico.” And: “Monarchs that spend the summer breeding season in western North America (including states west of the Rocky Mountains: Washington, Oregon, California, Idaho, and Montana) migrate to specific overwintering groves along the California coast roughly between Mendocino County in the north, and San Diego County in the South.”¹

The U.S. Fish and Wildlife Service: “The eastern population encompasses upwards of 70% of the total North American monarch range,” and “the western North American migratory monarch population is generally found west of the Rocky Mountains.”² The Xerces Society names the western breeding states: “Each spring, the butterflies fan out across the West to lay their eggs on milkweed and drink nectar from flowers in Arizona, California, Nevada, Oregon, Washington, Idaho, and Utah.” It also reports that “the number of monarchs making the annual journey to coastal California has declined by approximately 95%.”⁵

The line is not always clean. Colorado Parks and Wildlife: “Colorado is unique in that we have monarchs from both populations in our state on either side of the continental divide.”⁶ And Arizona sends monarchs both ways; the Southwest Monarch Study reports that “Monarch butterflies in Arizona migrate to both Mexico and California.”⁷

The eastern range, generation by generation

Monarch Joint Venture: “Generation 1 eggs are laid from late March through April in the southern United States and northern Mexico. Generation 2 eggs are laid throughout much of eastern North America from late April through June. Generations 3 and 4 are laid throughout the northern part of the range of eastern migratory monarchs from late May through July (Generation 3) and late June through August (Generation 4).”⁸ So a yard in Texas sees the first generation’s eggs in spring, and a yard in Minnesota sees the third and fourth in summer. That difference is the whole reason a city guide for one place does not fit another.

In Canada, the breeding range, in the words of the government’s 2016 status report, “is south of the 50 degree latitude in Ontario, Quebec and the Maritime Provinces, and extends north to the 54 degree latitude through Manitoba, Saskatchewan and Alberta.”⁹

Where the fall flight funnels

In fall the eastern population funnels toward Mexico. The U.S. Forest Service: “Eastern North American monarchs fly south using several flyways then merge into a single flyway in Central Texas.”¹⁰ Texas Parks and Wildlife describes that flyway as “a 300-mile wide path stretching from Wichita Falls to Eagle Pass,” with a second one “along the Texas coast.”¹¹ Journey North, from the roosts people report: “monarchs follow two distinct flyways as they travel to Mexico, an Eastern Flyway and a Central Flyway. Only one flyway appears to lead directly to Mexico.”¹² In Texas and the southern plains, the fall pass is the main event and the spring pass is when the eggs are laid; that is what we call a flyover place. The Texas page has the dates.

Where some monarchs stay all year

The U.S. Fish and Wildlife Service: “There are also non-migratory monarchs that remain year-round at the southern end of their breeding range in North America, including in parts of Florida, the Gulf Coast and California.”² The Xerces Society: “In the continental U.S., resident populations occur in Florida, along the Gulf Coast, and in Southern California.”¹³ The University of Florida’s extension service: “Because of the warm climate and continuous availability of host plants, much of Florida’s monarch population stays in the state year-round and breeds continuously throughout the year. Year-round residents are more common in southern Florida, as cold winter temperatures in northern Florida can kill monarchs at any life stage.”¹⁴ Butterflies and Moths of North America: monarchs “may breed all year in Florida, South Texas, and southeastern California.”¹⁵

Hawaii is its own case. Monarchs there don’t migrate at all: the Fish and Wildlife Service notes that “non-migratory populations are found from islands in the Pacific Ocean to the western edge of Europe,” and Butterflies and Moths of North America lists the species as “present in Australia, Hawaii, and other Pacific Islands.”²¹⁵ None of our migration guides fits Hawaii, and we don’t make one.

Where they are rarely seen

Western Washington. The University of Washington’s Miller Library: “Monarch butterflies are not frequently seen in the Puget Sound region,” and the western milkweeds that Monarch Joint Venture recommends “may not be successful in the Puget Sound region; both species are found mostly east of the Cascades.”³ The Washington Butterfly Association: “During summer you are most likely to find them in riparian areas of eastern Washington where milkweeds are abundant. Since 2022, between 400 and 900 monarch sightings have been verified each summer in the Pacific Northwest.”¹⁶ So “rarely seen,” not “never.”

Alaska. We looked for a verified record and found none: iNaturalist’s research-grade records returned zero for the whole state when we checked on 23 September 2026, and Butterflies and Moths of North America gives the range as southern Canada south through the United States.⁴¹⁵ So we say “we couldn’t find a verified record,” which is what we know, and not “monarchs can’t live there,” which we don’t.

Thin records inside the range. Some places have monarchs in small numbers. Within 40 km of El Paso, for example, iNaturalist holds 88 research-grade sightings from 2018 to 2025, most of them in September through November.⁴ Low counts partly reflect how few people are looking, so a thin record softens a message; it never turns into “none.”

What the finder tells you

Enter a ZIP and the finder looks up your county and gives one of these answers. Each result names the source it rests on.

• Summer breeding. “Monarchs raise several generations here each summer. The last generation leaves for Mexico in fall.” Most of the eastern United States and southern Canada.¹⁸
• Flyover. “Monarchs pass through twice a year. Spring is when they lay eggs. In fall most are migrating and need flowers, though some fall egg-laying does happen.” Texas and the southern plains; Austin is one.¹¹
• Breeds and passes through. “Monarchs breed here in summer and pass through in numbers each fall.” Places like Oklahoma City and Kansas City, where Monarch Watch’s peak-migration table puts a real fall pass on top of a summer season.¹⁷
• Year-round. “Some monarchs here stay all year and don’t migrate, at the southern end of their breeding range.” Florida, the Gulf Coast and the Texas coast.²
• Western population. “You’re in the range of the western monarch, a separate and much smaller population. Our eastern guides don’t fit your yard.”⁵
• Western population, overwintering coast. “Western monarchs spend the winter in groves along this coast. Near those groves, experts advise not planting milkweed at all.” The Xerces Society wrote in 2018 that it suggests “milkweed of any species not be planted within one mile of monarch overwintering sites in California,” and in 2021 that “planting milkweed near overwintering sites (within 5 miles) has generally been discouraged.”¹⁸¹³ The two distances disagree, so the finder says “near” and cites both.
• Sparse. “Monarchs do come through here, but in small numbers, so no guide can promise you caterpillars.”⁴
• Rare. “Monarchs are rarely seen here,” with the reason. For Alaska: “We couldn’t find a verified record of monarchs here; it’s far north of where they breed.”³⁴
• Hawaii. “Monarchs live in Hawaii all year and don’t migrate.”²
• Still checking. Where no source draws a line, the finder says “We’re still checking your area” rather than guess. That covers Colorado outside the Denver area, where the divide has not been drawn county by county, and Puerto Rico. New Mexico is a different case: its counties carry a state default that no source has confirmed, so the finder gives an answer there at low confidence, and that is on our list to fix.

Three rules apply to every result. It names its source. It never says “never,” “always” or “guaranteed.” And where the record is empty, it says the record is empty.