While fall begins on September 22, leaf peepers in most parts of the United States will have to wait a few weeks until peak foliage time according to one prediction map.

The Smoky Mountains are one of the most popular places to catch leaves changing color, and its 2022 Fall Foliage Prediction map is a tool designed to help travelers time out the best time to visit.

The northernmost states in the contiguous U.S. are the first to see the changing of the leaves, and the trend trickles down slowly to the southernmost states.

Across the U.S., the peak foliage happens sometime within October 3 and November 21.

For Smoky Mountain visitors, the leaf peeping doesn’t get better than the week of October 31.

Indiana’s Brown County is a popular spot for leaf peeping in the Midwest, and peak foliage in that area will likely happen on October 31 as well.

If you can’t wait that long, the New England area, also beloved for its colorful fall leaves, will hit peak foliage around October 10th, according to the foliage prediction map.

Why do leaves change color?

Chlorophyll is the compound that gives leaves their green color and helps plants by converting sunlight into “food” through photosynthesis.

As the days get shorter and colder in the fall, chlorophyll in leaves breaks down and reveals the natural colors underneath like red, orange, and yellow.

The colors are based on chemicals in the leaves like carotenoids and anthocyanin, according to the Harvard Forest.

You can see the 2022 Fall Foliage Prediction map here.