New Mexico Nature Guide: September 2026
Data updated: August 2026Sources & method · Corrections
September is the golden turn in New Mexico — the aspen blaze along the Enchanted Circle, the red chile ristras hang at every stand, and the first sandhill cranes return to the Rio Grande. Hawk migration builds over the plains and the rabbitbrush gilds the high desert.
Week by week in September
September 3–9
- Rabbitbrush and broom snakeweed gild the roadsides; purple asters and gayfeather color the meadows and plains.
- Sandhill cranes begin trickling back to the Rio Grande Valley as the first cool fronts push south.
- Red chile ristras hang at every stand, apples ripen in the northern valleys, and piñon may appear in a good mast year.
- Aspen gold spreads downward through the high Sangre de Cristos and the Enchanted Circle begins to turn.
September 10–16
- Quaking aspen blaze gold across the high country; the Santa Fe ski basin and Enchanted Circle approach peak color.
- Raptor migration builds; Cooper's and sharp-shinned hawks and the first wintering ducks return to the wetlands.
- The Milky Way still arches overhead at nightfall, and the lengthening nights bring earlier dark for stargazers.
- Northern New Mexico apples from Velarde and Dixon reach the markets alongside late melons and red chile.
September 17–23
- Aspen gold peaks along the Enchanted Circle and the high Sangres — the marquee fall-color event of the New Mexico year.
- Broad-tailed and rufous hummingbirds thin out as the last migrants leave the mountains for the south.
- Monarch migration peaks down the Rio Grande corridor; painted ladies and sulphurs work the rabbitbrush.
- Harvest winter squash, the last chile, and pumpkins before the first frosts reach the high valleys.
September 24–30
- Cottonwoods begin turning gold along the Rio Grande bosque as the aspen color fades from the highest peaks.
- Sandhill crane numbers climb at the Bosque and the Middle Rio Grande as the great fall return gathers.
- Rabbitbrush holds its gold and chamisa scents the air after rain across the high desert.
- Apples, winter squash, pumpkins, and dried red chile dominate the late-September harvest markets.
Birds This Month
September is a major migration month in New Mexico, and the first hint of the coming winter spectacle appears. A rare vanguard sandhill crane may turn up in the Rio Grande Valley late in the month as the first cool fronts push south, the earliest hint of the great flocks that will pour in through October and fill Bosque del Apache by November. The first wintering ducks return to the wetlands, and raptor migration builds — Cooper's and sharp-shinned hawks move through the foothills, and the Swainson's hawks that gathered in August stream south in large kettles over the eastern plains.
The hummingbirds thin out. Broad-tailed and rufous hummingbirds dwindle at mountain feeders as the last migrants leave for the south, and by late September most of the high country is quiet of them. Migrant warblers, flycatchers, and sparrows still refuel in the bosque, and the desert and grassland birds prepare for the cooler season.
Wintering sparrows begin to return — white-crowned sparrows and dark-eyed juncos reappear at feeders as the high country cools.
This month's tip: watch the eastern plains for hawk kettles and the Rio Grande for the first cranes. September is the turning of the seasons in the bird world — the breeding birds leaving, the winter birds arriving — and a stray early crane is the first promise of the Bosque del Apache spectacle to come.
What's Blooming
September is the great rabbitbrush month in New Mexico. Rabbitbrush (chamisa) bursts into brilliant gold along roadsides, arroyos, and the high desert, its sharp, distinctive scent filling the air after rain — the signature late-season bloom of the New Mexico landscape, and a magnet for late butterflies and bees. Broom snakeweed adds more yellow to the grasslands and mesas.
The autumn flowers color the plains and mountains. Purple asters, gayfeather (blazing star), and goldenrod brighten the meadows and eastern grasslands, sunflowers linger along the roadsides, and the last desert zinnia and globemallow hold on in the southern deserts. In the high country, the meadow flowers fade as the first frosts approach and the aspen begin to turn.
Where to see it: drive almost any New Mexico highway now for the gold of the rabbitbrush, which lines the roads and washes statewide. The eastern plains hold the asters and gayfeather, and the high mountain meadows offer the last flowers of the season before the autumn color takes over. The combination of golden chamisa and turning aspen makes September one of the most visually striking months of the year.
Garden This Month
September is one of the most pleasant gardening months in New Mexico, as the monsoon winds down and the brutal heat eases into mild, sunny autumn days. The fall garden sown in August comes into its own — harvest lettuce, spinach, kale, chard, radishes, and beets as the cool-season crops thrive in the gentle weather, and keep picking the last of the warm-season harvest, including the final chiles (now reddening on the plants) and tomatoes.
Elevation governs the urgency. At higher elevations around Santa Fe and Taos, the first frost typically arrives in mid-to-late September, so watch the forecast and harvest tender crops, green chiles, and green tomatoes before a freeze, keeping row cover ready to extend the season. In the warmer central and lower valleys, frost is still weeks off and the season runs on. This is also the prime time to plant garlic and spring-flowering bulbs and to sow cover crops on finished beds, as the cooling soil is ideal for root establishment before winter.
Zone 6b (higher valleys, Santa Fe / Taos area): the first frost typically arrives in mid-to-late September here, so harvest the warm-season crops, chiles, and green tomatoes before a freeze, and protect the fall greens with row cover. Plant garlic late in the month for next summer.
Zone 7a (Albuquerque, mid-elevation valleys): the mild fall season favors the cool-season crops sown in August — harvest greens, lettuce, and radishes, and keep picking the last chiles and tomatoes. Plant garlic and spring bulbs as the soil cools, and sow a final round of fast greens.
Zone 7b (lower-mid valleys): the heat eases into a fine growing stretch — harvest the last melons and chiles, keep the fall garden producing, and plant garlic and cool-season transplants. Frost is still weeks away, so make the most of the gentle autumn weather.
What's at the Farmers Market
September markets in New Mexico shift toward the red harvest and the autumn fruit. Red chile comes into its own as the pods ripen on the vine and dry — whole pods, ground powder, and the iconic ristras appear at every stand, the strings of drying red chile that are a New Mexico cultural emblem. Choose deep, even red and fully dry pods for ristras, and hang them in a dry, airy spot out of direct sun. Late green chile roasting continues into early September.
The orchard harvest peaks. Northern New Mexico apples from the Velarde and Dixon orchards along the Rio Grande reach the markets in force — choose firm, heavy fruit and store it cold and apart from other produce. The last peaches, melons, and sweet corn round out the summer harvest, and in a mast year the first piñon nuts may appear.
The fall vegetables fill out the tables: winter squash, pumpkins, and the cool-season greens, carrots, and beets from the fall plantings. For storage, keep winter squash in a dry, ventilated spot where it holds for weeks, refrigerate the greens and roots, and shop the Santa Fe and Las Cruces markets early for the apples and red chile at their autumn best.
Night Sky This Month
September is a fine transitional stargazing month in New Mexico, as the nights lengthen past the equinox and the summer Milky Way still arches overhead in the early evening. The state's dark-sky destinations — Chaco Culture National Historical Park, Clayton Lake State Park, the Gila's Cosmic Campground, Capulin Volcano, and the Bootheel ranchland — offer crisp, clear autumn skies as the monsoon clouds give way to drier air.
The sky is in transition from summer to fall. The Summer Triangle of Vega, Deneb, and Altair rides high overhead at nightfall, and the bright core of the Milky Way sinks lower in the southwest each evening. Rising in the east, the Great Square of Pegasus heralds the autumn constellations, with the faint chain of Andromeda beside it — and from a truly dark New Mexico site, the Andromeda Galaxy, the most distant object visible to the naked eye, glows as a soft smudge.
September has no major meteor shower, leaving the month to the changing constellations and the Andromeda Galaxy, a fine binocular target from a dark site. For planet positions and viewing this year, check the printable New Mexico night-sky guide for your latitude and date.
Butterflies & Pollinators
September keeps New Mexico's butterflies active as the fall migration builds and the rabbitbrush blooms. Monarch migration continues down the Rio Grande corridor and across the eastern plains toward Mexico, with the golden rabbitbrush (chamisa) serving as a vital nectar source for the southbound travelers. Queens, painted ladies, and a wealth of sulphurs work the rabbitbrush, asters, and late sunflowers.
The diversity remains high as the season turns. Marine blues, hairstreaks, skippers, and the late-season two-tailed and black swallowtails stay on the wing in the deserts, grasslands, and gardens, fueling up on the abundant fall flowers. As frosts begin in the high country, the mountain species wind down, but the warm lowlands keep their butterflies busy through the month.
To prepare for the season ahead: the blooming rabbitbrush along arroyos and roadsides is the season's great butterfly magnet — leaving it standing (rather than cutting it back) provides essential late nectar for migrating monarchs and other species. Keep garden asters, zinnias, and salvia blooming, and maintain native milkweed for the last passing monarchs as they head for their Mexican overwintering grounds.
What to plant for them is in the New Mexico native plants guide
Trees This Month
September is the start of New Mexico's spectacular fall color, and it begins high. The quaking aspen of the high country turn brilliant gold, the color spreading downward from timberline through the month — the Enchanted Circle around Wheeler Peak, the Santa Fe ski basin, and the high Sangre de Cristos and Jemez approach their peak in the second half of September, drawing leaf-peepers from across the region. Aspen gold against dark spruce and blue sky is the marquee autumn sight of the New Mexico mountains.
The lower trees begin to follow. The foothill Gambel oak turns russet and bronze, and late in the month the Rio Grande cottonwoods of the bosque start to gild along the river, the prelude to October's golden valley. The two-needle piñon — the state tree — drops its ripe nuts in a mast year, a wild harvest that comes only every few years and draws people into the woodlands to gather it. The evergreen conifers — ponderosa, spruce, fir — hold the dark backdrop against which the gold aspen blaze, and the desert mesquite and hackberry begin their slow turn toward dormancy.
The New Mexico native plants guide covers what grows with them
Weather & Daylight
Across New Mexico, a typical September day averages a high near 80°F and a low near 51°F, with about 1.8 inches of precipitation — statewide averages from the 1991–2020 U.S. climate normals.
Late-summer heat lingers near 80 with heavy afternoon showers, while nights near 51 finally start feeling cooler.
| Average high | 80°F |
|---|---|
| Average low | 51°F |
| Precipitation | 1.8 in |
| Sunrise (mid-month) | 6:47 MT |
| Sunset (mid-month) | 19:13 MT |
Figures are statewide averages over the 1991–2020 U.S. climate normals; local conditions vary with elevation and distance from the coast. Sunrise and sunset are computed for a midstate point on the 15th (MT).
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One short note when New Mexico's next month turns — what's arriving, blooming, and worth a night outside.
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Same month elsewhere: September in New York · September in North Carolina · September in North Dakota