Summer: It's over.
Extreme heat: outta here.
Hiking conditions: just about perfect.
Autumn in the Tucson area can be near nirvana for trail trekkers - with almost all of our desert, canyon and mountain terrain free from climatic extremes.
The Catalina Mountains and other ranges typically are cool but not cold right now, and autumn color on the mountain heights usually peaks in October.
Mile-high Madera Canyon south of Tucson is a hiker's heaven.
Desert trails near the city beckon when the sizzle of summer is on the wane.
Today, to help you answer the call of fall, we describe three trails to try. One offers cool mountain air and leafy color in the Catalinas, another traces a lovely watercourse in Madera Canyon, and a third weaves its way up a saguaro-studded ridge west of Tucson.
Your mission: Choose one of the routes. Pull on your boots. Go.
ASPEN-MARSHALL GULCH LOOP
Tale of the trail: The 3.7-mile route, high in the Catalina Mountains north of Tucson, serves up a brisk workout in forests tinted with fall color.
Along the way: You'll see - yep, voila! - aspen trees on the Aspen Trail leg of the loop route.
Some terrain along the trail was burned in the 2003 Aspen Fire, but young aspens, oaks and evergreens are busy refurnishing the forest.
Watch for splashes of yellow and gold - usually at their best in mid- to late-October. But be aware this is a subtle version of autumn - not the big fall fireworks you might see in Colorado or Vermont.
Other plants that have flourished since the fire - including abundant ferns - add their own touch of autumn in hues of copper and brown. Early in the fall, you might even spot a few leftover wildflowers in bloom.
Watch for a faint, unsigned side trail to the left after you've hiked two miles or so up the Aspen Trail. The side trail leads to a spot known as Lunch Ledge, a rocky overlook that's perfect for a trail snack or, well, lunch.
After following the Aspen Trail for about 2 1/2 miles and reaching Marshall Saddle, pick up the Marshall Gulch Trail to return to the starting point.
Winding on a mostly downhill course, the Marshall Gulch Trail takes hikers through stream-side terrain into lovely groves of maple trees.
When conditions are right, the autumn-red hues of maple leaves make this one of the most colorful stretches of trail in the Catalinas.
Get there: Take Tanque Verde Road to the Catalina Highway ($5-per-vehicle fee) and follow the highway past Milepost 24 to the community of Summerhaven.
Drive through Summerhaven and continue about a mile south to a picnic area and parking lot in Marshall Gulch. Trailheads for both segments of the loop are adjacent to the parking lot.
Tale of the trail: Madera Canyon south of Tucson is home to plenty of challenging trails - but some of the canyon's most splendrous scenery is along a route accessible not only to hikers, but people in wheelchairs.
Along the way: The 0.7-mile Accessible Trail winds at first through enchanting woodlands of mesquite and oak set against the backdrop of a rugged rock summit called Elephant Head.
But that's just an introduction. The surfaced, mostly flat route quickly changes personality when it enters a riparian, or stream-side, zone along Madera Creek.
Here, walkers and visitors in wheelchairs pass towering cottonwood trees and other vegetation well watered by the creek.
That creek - sometimes flowing briskly with water from late summer and fall rains - provides a splendid aqueous soundtrack as it gurgles downstream and plunges over small waterfalls.
Birds are abundant, and it's not uncommon to see deer along the trail.
Other attractions include a surviving adobe wall of a historic canyon landmark known as the White House and small "bat houses" mounted on tall poles. They were erected to serve as dwellings for the area's bat population.
Be sure to take a camera. Even professional photographers find lots to like along the Accessible Trail.
Bruce Griffin, whose large-format photos have appeared in publications such as Arizona Highways magazine, visited the area one day recently in a quest for yet another intriguing image.
Get there: From Tucson, take Interstate 19 south to Green Valley and get off at the Continental Exit. Continue southeast to Madera Canyon ($5-per-vehicle fee) and the Proctor Parking Area. The trail begins there. Pets must be leashed.
BROWN MOUNTAIN TRAIL
Tale of the trail: The 2.4-mile route connects two trailheads in Tucson Mountain Park west of the city - serving up big views from a saguaro-studded ridge.
Along the way: Traversing classic Sonoran Desert terrain, the Brown Mountain Trail would bring on a severe avoidance reaction from many hikers in the days of midsummer.
This month and next, as the weather gradually cools, it once more becomes a trail of multiple attractions.
One of those scenic lures is the route's impressive population of enormous cholla cacti.
Observe also the barrel cacti - hearty fat specimens, some of them holding red-orange blooms even as summer makes its exit.
High in the sky: turkey vultures, and perhaps a soaring hawk.
The trail starts low at both trailheads and climbs to a craggy ridge near the midpoint - gaining only a few hundred feet in elevation.
The highest point - about 3,100 feet - isn't likely to bring on a nosebleed, but it's enough to give hikers a good, hawk's-eye look over an expanse of desert and mountains. The view includes the cactus forests of nearby Saguaro National Park West, the vast Avra Valley and the summit of Mount Wrightson south of Tucson.
Get there: Follow Speedway west out of Tucson and continue as it becomes Gates Pass Road. Cross the pass and proceed to an intersection with Kinney Road. Turn right (northwest) onto Kinney Road and follow it 0.6 of a mile to a left (southwest) turnoff for McCain Loop Road. Continue about 0.4 of a mile to the trailhead.
A trailhead at the opposite end of the route is at the Juan Santa Cruz Picnic Area on Kinney Road just southeast of the Arizona-Sonora Desert Museum.
Leave dogs at home.
Coming Sunday: Autumn color guide
See the ¡Vamos! section in the Arizona Daily Star Sunday for a guide to sites known for good displays of fall color.