Colorado Nature Guide: April 2026
April is full spring on the Colorado plains and Front Range, even as heavy wet snow still falls and the high peaks stay white. Songbirds pour back into the cottonwoods, the prairie grouse leks reach their peak, golden banner and spring beauties carpet the foothills, and the orchards of the Western Slope froth into bloom.
What to look for this week
- Bald eagles fish the open tailwater below the South Platte and Arkansas reservoir dams as the lakes freeze.
- The Quadrantid meteor shower peaks around January 3 in a short, sharp burst best seen after midnight from a dark San Luis Valley sky.
- Deep-soak Front Range trees and evergreens on any warm, unfrozen day — winter desiccation, not cold, kills the most plants here.
- The bare plains cottonwoods along the rivers reveal the bulky stick nests of red-tailed hawks and eagles.
Birds This Month
April is a month of arrivals across Colorado's lowlands. Songbird migration builds steadily in the cottonwood corridors of the South Platte and Arkansas rivers and the Front Range foothill canyons — the first Bullock's orioles, western kingbirds, house wrens, yellow warblers, green-tailed towhees, and a sweep of returning sparrows arrive, and the dawn chorus thickens by the week. Broad-tailed hummingbirds return to the foothills, their wing-trill a sure sign of spring, and white-throated swifts wheel along the hogback cliffs.
The prairie grouse leks reach their peak in early April. Greater prairie-chickens boom near Wray, greater and the Colorado-endemic Gunnison sage-grouse strut near Gunnison and Crawford, and sharp-tailed grouse dance in the northwest, all best seen in the first hour of light. Out on the eastern plains the state bird, the lark bunting, returns to the short-grass country, the males singing in fluttering display flights, and Mountain plovers arrive on the bare prairie of the Pawnee region.
Waterbirds move through in force. American avocets, black-necked stilts, Wilson's phalaropes, and a parade of shorebirds gather at plains reservoirs and playas, and the last sandhill cranes drift north out of the San Luis Valley.
This month's tip: hang a hummingbird feeder by mid-April along the Front Range foothills to greet the returning broad-tailed hummingbirds, and listen for the metallic wing-trill of the males as they set up territories.
What's Blooming
April is when the Colorado foothills and plains truly bloom, while the high country stays under snow. The Front Range foothill slopes light up with golden banner (Thermopsis), spreading sheets of bright yellow pea flowers, and the first spring beauties, sand lilies, and Easter daisies peak on the mesas and grasslands. The silky pasque flowers continue on the cooler slopes, and the first Nuttall's violets and chiming bells (Mertensia) open in moist foothill draws.
On the warming plains, the scarlet globemallow, locoweeds and milkvetches, and the first prickly poppies begin, and the foothill shrublands brighten as the wild plum, chokecherry, and serviceberry thickets froth into white bloom along the draws. The boulder raspberry opens its big white roselike flowers on rocky Front Range slopes. The mesas and lower canyons of the Western Slope and the foothills above the Front Range cities offer the richest April flower-walking, with the great alpine show still three months away on the peaks above.
Garden This Month
April is prime planting season for the Colorado cool-season garden along the Front Range and lower elevations. As soon as the soil works, direct-sow the full cool-season list — peas, spinach, lettuce, radishes, carrots, beets, chard, and cilantro — and set out onion sets, seed potatoes, and brassica transplants. These crops thrive in the cool, bright spring and want to size up before the intense early-summer sun and heat arrive.
The hard rule, repeated because transplants from milder climates keep breaking it: do not set out tomatoes, peppers, squash, or any tender crop yet. The average last frost along the Front Range is mid-to-late May, and April is one of the snowiest months of the year here — heavy, wet 'April snows' regularly bury blooming trees. Keep warm-season transplants hardening off in a protected spot, plant bare-root and balled trees, shrubs, asparagus, and rhubarb, and keep watering newly planted and woody plants deeply through the dry, windy spells between snows.
Zone 4b (mountain towns and high foothills): the cool-season window finally opens at the end of the month. As the soil thaws and dries, direct-sow peas, spinach, radishes, and arugula under cover, and set out onion sets late in the month. Keep all warm-season transplants indoors and protected — the last frost here is still a month or more away, deep into May or June.
Zone 5b (Front Range cities — Denver, Boulder, Fort Collins, Colorado Springs): prime cool-season planting. Direct-sow peas, spinach, lettuce, radishes, carrots, beets, chard, and cilantro, set out onion sets, seed potatoes, and brassica transplants, and plant cool-season flowers. Keep tomatoes and peppers hardening off but unplanted — the average last frost is still mid-May, and a heavy April snow is common.
Zone 6a (warmest Front Range and lower Western Slope — Grand Junction area): the season is well underway. Get all the cool-season crops in early, set out onions and potatoes, and begin hardening off warm-season transplants for setting out late in the month or early May once frost danger truly passes. Watch for a late freeze that can still nip the fruit blossoms.
What's at the Farmers Market
Colorado markets green up steadily in April as the high-tunnel season hits full stride and the earliest outdoor markets prepare to open. The tables fill with abundant tender greens — spinach, leaf lettuces, arugula, kale, tatsoi, salad mix, and microgreens — alongside radishes, green onions, the first chives and cutting herbs, and bunches of rhubarb.
The storage crops carry on — San Luis Valley potatoes, storage onions, and carrots — and the vegetable, herb, and flower starts are now front and center at growers' stalls for home gardeners. Colorado pantry staples continue: local honey, eggs, grass-fed beef, bison, and lamb, milled flour, and dried pinto beans. In the warmest gardens, the first cut asparagus may begin appearing late in the month.
For selection and storage: store tender greens dry and loosely bagged and use them within a few days; keep rhubarb stalks dry and refrigerated; and harden off any vegetable starts you buy before setting them out, since a freeze is still very much on the table. Keep stored potatoes and onions cool, dark, and airy.
Night Sky This Month
April is the heart of the spring sky over Colorado, and the dark-sky destinations are warming into a more comfortable observing season. Make for Great Sand Dunes National Park beneath the Sangre de Cristos, the dark-sky community of Westcliffe-Silver Cliff in the Wet Mountain Valley, Black Canyon of the Gunnison, Dinosaur National Monument, or Jackson Lake State Park on the plains. The high, dry air still delivers superb transparency, and the milder nights make stargazing far more pleasant than midwinter.
The spring constellations now own the evening. Leo the Lion rides high in the south, the Big Dipper stands overhead with its handle arcing down to brilliant orange Arcturus in Boötes, and blue-white Spica follows in Virgo. The Lyrid meteor shower peaks around April 22, a modest but reliable shower whose meteors radiate from near the bright star Vega rising in the northeast late in the night. This is also prime galaxy season — the Virgo Cluster and the galaxies of Leo are at their best in a dark sky.
Because planet positions and the exact Lyrid peak shift each year, check the printable Colorado night-sky guide for this year's specific viewing nights and planet visibility from your latitude. Pick a clear night behind a passing front for the steadiest seeing.
Butterflies & Pollinators
April brings a real flush of butterflies to Colorado's plains and foothills. The overwintering adults — mourning cloaks, Milbert's tortoiseshells, and the commas — are joined now by waves of fresh spring fliers. The spring azure and the tiny Western pygmy-blue's relatives dot the foothill edges, the orange-tipped Sara orangetip patrols the streams, and the first cabbage whites, checkered whites, and orange sulphurs work the warming roadsides and gardens.
The big swallowtails appear in the foothill canyons and river corridors — western tiger swallowtails sail along the cottonwood and willow draws, and the dark two-tailed swallowtail, the largest butterfly in the West, glides through the foothill canyons. The first painted ladies and red admirals push north from the south, sometimes in great migratory waves. The high-country and alpine species, including the state insect Colorado hairstreak, remain dormant in the still-frozen mountains. Plant or protect native milkweed shoots now and let early nectar — golden banner, wild plum, chokecherry bloom, and dandelions — stand to fuel the season's first flights.
Trees This Month
April leafs out the Colorado lowlands while the high country waits. Along the plains and Front Range waterways, the great plains cottonwoods break into pale-green leaf, the willows and boxelders green the creek bottoms, and the foothill chokecherry, wild plum, and serviceberry thickets froth white along the draws. The peachleaf and other willows and the cottonwoods shed early pollen.
The showpiece of the month is the Western Slope orchard bloom: around Palisade, Paonia, Hotchkiss, and Cedaredge, the peach, apricot, cherry, plum, apple, and pear orchards burst into pink and white bloom, a fragrant high-stakes spectacle that growers watch nervously, because a single hard late freeze can wipe out the year's fruit. Across the Front Range cities, the ornamental crabapples, flowering pears, and maples color the streets. Up in the mountains, the quaking aspen begin to swell their buds at the lowest elevations, the first hint that the green wave will soon start its long climb up the slopes.
Go deeper with the Colorado guides
The complete Colorado birding, native-plant, wildflower, and night-sky guides — or the whole year in one bundle.
Same month elsewhere: April in Connecticut · April in Delaware · April in Washington, D.C.