Here's when the fall leaves will reach peak color in Seattle

When to see fall colors in Seattle, WA

Autumn is here, and FOX 13 Meteorologist Abby Acone gives us an idea of when the leaves will start changing colors in Seattle and across the Pacific Northwest.

SEATTLE - Fall has arrived and areas in western Washington are starting to see some fall foliage. Here's when those fall colors are expected to peak this year.

Those who have lived in the area for a while know that Seattle and areas around Puget Sound will become a leaf-peeping paradise before "the big dark" of winter. Let's talk about where we stand right now, when fall colors will peak and why leaves change color in the first place.

WASHINGTON, UNITED STATES - 2016/09/24: Fall colors at the meadows at Paradise in Mt. Rainier National Park in Washington State, USA. (Photo by Wolfgang Kaehler/LightRocket via Getty Images)

Earlier this week, some of the highest elevations in the Rocky Mountains reached peak fall colors. In Washington, we have more time to go. However, the state's mountain ranges are already starting to see some fall foliage, specifically in the Selkirk Mountains north of Spokane, the Cascades and the Olympics.

Though the leaves are starting to change in the Puget Sound lowlands, this region is marked as having "little to no color" as of Monday. The same goes for areas in central Washington and the Columbia Basin.

As cooler weather returns to Western Washington this fall, the autumn colors should peak in Seattle in mid October.

The fall colors will peak in Seattle in mid October. (FOX 13 Seattle)

When will fall colors peak in Seattle and western WA?

We are expecting to see fall colors peak in western Washington by mid-October, especially along the Olympic and Cascade Mountain ranges. Areas in the Puget Sound lowlands will be slightly delayed, with colors peaking around October 21.

UNITED STATES - 2007/09/01: View of Mount Rainier from Pinnacle Peak trail with mountain blueberries in fall colors in Mount Rainier National Park, Washington State, USA. (Photo by Wolfgang Kaehler/LightRocket via Getty Images)

The fall colors won't lose their hue before Halloween. Western Washington is home to larches, maples, dogwoods, and cottonwoods, all renowned for maintaining their vibrant colors well into early November.

Why do leaves change color?

Chlorophyll, which is the chemical that gives leaves their green color, thrives in the summer because of all the sunlight.

As the seasons change and the weather starts to cool down, chlorophyll breaks down, and those leftover chemicals help the leaves turn yellow, orange and red.

Bright fall colors are more likely when late summer is dry and autumn has sunny days and cool nights.