The adult male has a black face and chin, a glossy purple gorget, and a dark forked tail.

Trend maps for black-chinned hummingbirds showed a relatively stable population between 2009 and 2019, albeit with some decline in late years of that decade.

[12][13] Black-chinned hummingbirds are found in most of the western United States, reaching north into Canada in Alberta and British Columbia, east to Oklahoma, and as far south as Mexico.

Their breeding habitat is open, semiarid areas, usually near water in the western United States, northern Mexico, and southern British Columbia.

[16] In courtship, males perform "pendulum" display, flying back and forth in wide U-shaped arcs, making whirring sounds on each dive.

[17] Black-chinned hummingbirds can exhibit territorial behavior around feeders as well as at other small feeding sites, becoming more defensive during breeding season.

The female builds a well-camouflaged nest in a protected location in a shrub or tree using plant fibers, spider web silk, downy feathers and lichens.

Black-chinned hummingbirds prefer to nest 6–12 ft (1.8–3.7 m) above the ground, often on exposed horizontal branches below the canopy.