Quick overview: The Southwest isn't a "one species, one timeline" region like most of the country — it's home to more overlapping hummingbird species than anywhere else in the US, each with its own distinct schedule. Costa's Hummingbirds are active in the low desert nearly year-round; Black-chinned and Broad-billed arrive from April through September; and southeastern Arizona's "sky islands" host rare specialties like Broad-tailed, Lucifer, and Magnificent Hummingbirds, with activity peaking from late July through early September as summer monsoon rains trigger a second wave of native blooms. Keep at least one feeder up nearly year-round in the low desert, and don't be surprised if your visitor lineup genuinely changes with the seasons rather than staying consistent.

What Makes This Region Different

Every other region in this series can be summarized around one or two dominant species and a single migration window. The Southwest can't be — it's the most hummingbird-diverse region in the entire country, with Arizona alone hosting 15+ recorded species. What makes this especially distinctive is the monsoon effect: unlike anywhere else covered in this series, much of the Southwest sees a genuine second seasonal pulse of activity each year, driven by summer monsoon rains (typically July through September) that trigger a fresh wave of native desert blooms — a phenomenon regional birders and Audubon call the desert's "second spring." This means peak hummingbird diversity here often arrives in mid-to-late summer, not spring.

The Hummingbirds You'll See in This Region

Black-chinned Hummingbird is the most widely distributed species across the Southwest, found from low desert up into higher elevations across Texas, New Mexico, and Arizona. Males show a velvety black throat with a thin band of violet-purple visible only in direct light.

Costa's Hummingbird is a true desert specialist, common around Phoenix, Tucson, and similar low-desert areas, especially in winter. Males have a dramatic, flared iridescent purple crown and throat, and time their nesting to the desert's earliest winter and spring bloom.

Broad-billed Hummingbird is a Southwest specialty most common in oak-studded canyons of southeastern Arizona, with an unmistakable orange-red bill tipped in black and an iridescent blue-green throat.

Buff-bellied Hummingbird appears along the Texas Gulf Coast and Rio Grande Valley as a genuine year-round resident, distinguished by its soft tan belly and reddish bill.

Southeastern Arizona's "sky island" mountain ranges — the Huachucas, Chiricahuas, and Santa Ritas — are where the Southwest's diversity peaks, hosting rarities like Violet-crowned, Magnificent (Rivoli's), Blue-throated Mountain-gem, and Lucifer Hummingbirds, most active from late July through early September.

Migration Timing by Sub-Region

Pop's tip: If you're near the sky islands of southeastern Arizona, plan a visit — or simply pay closer attention to your own feeder — during the monsoon window of late July through early September, when species diversity in this specific area rivals anywhere else in the country.

Where They're Coming From, and Where They're Headed

Most Southwest hummingbirds winter in Mexico and move north as the desert's earliest blooms begin, often well before more northern regions see any migration activity at all. Because elevation varies so dramatically across this region — from below sea level near Yuma to well over 8,000 feet in Arizona's sky islands — timing is driven as much by elevation as by calendar date or latitude, with high-country arrivals often lagging weeks behind the low desert even at the same latitude.

The monsoon season adds a genuine second ecological pulse: as summer rains trigger fresh native blooms in July and August, some species shift activity patterns or arrive specifically to take advantage of that renewed nectar source, rather than following a single spring-arrival, fall-departure pattern.

How We Know This

Species range, arrival, and departure timing referenced in this guide draw on data compiled by the Cornell Lab of Ornithology's All About Birds and eBird platforms, which aggregate millions of citizen-reported sightings to map real-time migration patterns. The mechanism behind migration timing itself — driven by day length and hormonal changes rather than food or temperature — is confirmed by researchers at the National Audubon Society. The Southwest's monsoon-driven "second spring" effect on hummingbird diversity is documented by Audubon, which cites hummingbird researcher Sheri Williamson's field observations of the sky islands' late-July surge in both breeding and migrating species.

Should I Take My Feeder Down in Fall?

In most of the Southwest, the standard rule applies: leaving a feeder up doesn't delay or prevent migration, since timing is governed by day length and hormonal cues, not food availability. But the low desert is a genuine exception, much like the Gulf Coast in the Southeast — Costa's Hummingbirds are present much of the year, and Anna's Hummingbirds increasingly show up through the colder months as well.

Practical recommendation: keep at least one feeder up nearly year-round in the low desert. In the sky islands and high country, maintain feeders through September to catch the tail end of monsoon-driven activity.

How to Help Hummingbirds Through This Region

• Low desert residents: keep a feeder up nearly year-round rather than seasonally, given resident Costa's and increasingly common wintering Anna's Hummingbirds.
• Sky island and high-country residents: don't take your feeder down too early — some of the region's rarest species are most active in late summer, not spring.
• Time visits or extra attention to the monsoon window (late July–early September) if you're near southeastern Arizona's canyons, when species diversity peaks.
• Keep nectar fresh — change every 1-2 days during intense desert heat, since nectar spoils especially fast in high temperatures.
• Add a comfortable perch or swing near your feeder, ideally positioned with some afternoon shade given the region's intense sun.
• Plant regionally-suited natives — chuparosa, desert willow, and various penstemon species are strong performers, with specific varieties suited to low desert versus higher elevations.

Frequently Asked Questions

Why does the Southwest have so many more hummingbird species than other regions? The Southwest sits at the meeting point of several biogeographic zones — desert, mountains, grassland, and riparian forest — combined with proximity to Mexico, giving it access to species found nowhere else in the country, especially in southeastern Arizona's sky island mountain ranges.

What is the monsoon effect on hummingbird activity? Summer monsoon rains, typically arriving in July and August, trigger a fresh wave of native desert blooms, creating a genuine second seasonal pulse of hummingbird activity that often rivals or exceeds spring migration in parts of the Southwest.

Should I keep my feeder up year-round in the Southwest? In the low desert, yes — Costa's Hummingbirds are present much of the year, and Anna's Hummingbirds are increasingly seen through winter as well. In higher elevations and sky island areas, maintaining feeders through September captures the tail end of monsoon-driven activity.

When is the best time to see the most hummingbird species in the Southwest? Late July through early September in southeastern Arizona's sky island mountain ranges, when monsoon-driven blooms bring both resident and specialty species together at their most active.

Does elevation affect hummingbird timing in the Southwest? Yes, significantly. Because the region spans elevations from below sea level to over 8,000 feet, high-country arrivals can lag weeks behind low-desert areas even at the exact same latitude.

Summary: Key Takeaways for Hummingbird Migration in the Southwest

• The Southwest hosts more hummingbird species diversity than any other US region, with Arizona alone recording 15+ species
• Monsoon rains (typically late July–early September) trigger a genuine second seasonal activity pulse, distinct from the spring-arrival pattern seen elsewhere — a phenomenon Audubon and regional researchers call the desert's "second spring"
• Costa's Hummingbirds are active in the low desert nearly year-round; keep at least one feeder up there continuously
• Elevation affects timing as much as latitude — high country and sky island arrivals can lag weeks behind the low desert
• Southeastern Arizona's sky islands offer the single best diversity window in the country, peaking in late summer rather than spring
• Timing and species data referenced throughout draw on Cornell Lab of Ornithology (eBird, All About Birds), National Audubon Society research, and field observations from hummingbird researcher Sheri Williamson

At Pop's Birding, we believe every backyard — big or small — has room for a little more wonder. Explore our feeders, nectars, swings, and wildflower seed blends to start building your own hummingbird sanctuary today.