Allow me to let you in on a little secret: September is the best month in the Sierra Nevada.

April and May have their swollen rivers and gushing waterfalls. July has the longest, warmest days. Even February, pinnacle of winter, has its snowy, white charm.

But September, in so many ways, trumps them all:

Goodbye, crowds

Labor Day weekend marks the end of the traditional vacation season. Now that the kids are back in school, it's time for the grown-ups to come out and play.

In September, you don't have a problem securing a wilderness permit — even on the most popular trails.

In September, campsites that are jam-packed in July and August sit practically empty.

In September, the only sound you hear on most hikes is the thud of your footsteps.

"It's magical out there right now," said Ken Karst, an avid hiker who works for DNC Parks and Resorts, Yosemite's concessionaire.

Goodbye, bugs

Remember all those blood-thirsty mosquitoes that terrorized park visitors in the spring and early summer?

Poof! They're gone.

Three generations of the Frey family took advantage of the light traffic between Tioga Pass and the Gaylor Lakes region on an early September day. A declining insect population, fewer crowds and the region's natural beauty make the fall a good time to visit the Sierra Nevada. Eric Paul Zamora / The Fresno Bee

Mosquitoes perish in the fall for two reasons: most standing water dries up, and nighttime temperatures are too cold for bugs to reproduce.

So unless you're planning to hike through a bog, it's safe to leave the DEET in the car.

Your skin will thank you.

Hello, color

Whenever I hear someone complain that California never gets autumn color displays like those in New England, my response is a knowing smile.

Those people must not spend September in the Sierra.

While evergreens get most of the attention, the Sierra is packed with groves of deciduous trees that can't wait to display their colors. Quaking aspens turn flaming yellow. Dogwoods become crimson. Even grasses and ferns take on a golden hue.

I'll let naturalist John Muir take over from here, in his trademark Victorian prose:

"The foreground was now aflame with autumn colors, brown and purple and gold, ripe in their mellow sunshine; contrasting brightly with the deep, cobalt blue of the sky, and the black and gray, and pure, spiritual white of the rocks and glaciers."

Light show

Ever wonder why Muir nicknamed the Sierra Nevada (Spanish for "snowy range") the Range of Light?

Go in September.

Something magical happens when the sun traces a lower path across the sky. The mountains, forests and meadows become drenched in a soft, yellow hue.

Days are not as long in September as they are in summer. By mid-afternoon, when shadows begin their daily creep, you might feel a hint of approaching winter.

Alpenglow, that magical time between sunset and night, becomes more pronounced in September. As the fading light becomes softer, yet richer, gaze overhead and you'll notice the sky has become a deeper shade of blue. Then one or two stars start to appear. Then 10 or 15. Before long, the sky is dotted with them.

Few places are better suited to enjoy a Sierra September than Tuolumne Meadows in the Yosemite high country.

The Tuolumne Meadows area of Yosemite offers a mix of easy-to-navigate hiking trails and picturesque scenery. With the crush of tourists over, September is a good month to explore the region's waterways and peaks. The area also dispels the myth that California's seasons pale in comparison to those on the East Coast. Eric Paul Zamora / The Fresno Bee

At 8,600 feet, Tuolumne Meadows is a blend of granite domes, forests, peaks and meadow grasses.

Although most of the crowds have gone, the Tuolumne Meadows campground is open through Sept. 25 and the nearby cafe and store until Sept. 26.

Other Sierra locales that merit a September visit include Mono Hot Springs in the Sierra National Forest, Paradise Valley in Kings Canyon National Park and the Sierra Vista Scenic Byway past North Fork.

Go now. Thank me later.