2022 Fall Foliage Peak Map: Best Time To See Leaves In Illinois

ILLINOIS — Although fall won't officially begin until Sept. 22, many are already itching to see the leaves change and the air get chillier.

In Illinois, peak fall foliage won’t begin until October, according to the 2022 Fall Foliage Prediction Map, which was released Friday. In northern Illinois, partial fall foliage will be seen in the northernmost part of the state near the Wisconsin border the week of Oct. 10. By Oct. 17, that part of the state will be at near-peak fall foliage, reaching its peak the week of Oct. 24. The rest of the Chicago area will be at near-peak fall foliage the week of Oct. 24 and will see the peak the week of Oct. 31, right around Halloween.

David Angotti, an expert on statistics who lives in Tennessee, was in the property management business in 2013 when he created the first Fall Foliage Prediction Map for SmokyMountains.com to help visitors plan their vacations when autumn leaves are the most brilliant.

No predictive tool is 100 percent accurate, but it can give you a pretty good shot at seeing autumn leaves when they turn their most blazing reds, vibrant orange and sunny yellows.

Tens of millions of people use the map every year to plan vacations, weddings and photography trips, but the most common use is by people who want to check out leaves closer to home.

“What started as a fun side project quickly became the most respected nationwide fall leaf map and one of the best fall resources in the country,” Angotti said in a news release.

This year, the data scientists will incorporate reports from map users to update the map late September. The backbone of the map is meteorology — temperature, moisture, sunlight and precipitation — but it incorporates historical and forecast data, including National Oceanic and Atmospheric Administration precipitation forecasts, elevation, actual temperatures, temperature forecasts and average daylight exposure to develop each county’s fall baseline date.

New maps are created every year.

For the second year, the map creators included the top places to see fall leaves in Illinois to help you plan leaf peering trips. Among them:

• Cap Sauers Holding Nature Preserve in Palos Park
• Matthiessen State Park in La Salle County
• Pere Marquette State Park in southern Illinois

Once Angotti created the map for visitors to the Smokies, they then wanted to know about peak leaf peering times in other parts of Tennessee, so he decided to collect data for the entire country.

Smokymountains.com

To use the map, simply slide the scale to the right to see when leaves will peak in your state. Zero in on your county, and you'll be able to decide whether it's best to plan a northern, southern, eastern or western route.

Areas shaded in green have not begun to change color. As the season progresses, the map shows a progression of colors. When areas are shaded in brown, the leaves are past their peak.

There’s more than shorter days, longer nights and falling temperatures to signal to trees that it’s time to prepare for winter. The predictive map uses a complex algorithm that analyzes several million data points and spits out about 50,000 predictive data pieces.

This allows for a county-by-county forecast on the precise day the peak should occur. This year, the formula will get a mid-season update in late September that will pull in the latest data to increase the accuracy and usefulness of the tool.

What Causes The Different Colors

You probably remember from science class that the color change all starts with photosynthesis. Leaves constantly churn out chlorophyll — a key component in a plant’s ability to turn sunlight into the glucose it needs to thrive — from spring through early fall. Those cells saturate the leaves, making them appear green to the human eye.

But leaves aren’t green at all. Autumn is the time for leaves’ big reveal: their true color, unveiled as chlorophyll production grinds to a halt. The colors in fall’s breathtaking tapestry are influenced by other compounds, according to the national park’s website.

Beta-carotene, the same pigment that makes carrots orange, reflects the yellow and red light from the sun and gives leaves an orange hue.

The production of anthocyanin, which gives leaves their vivid red color, ramps up in the fall, protecting and prolonging the leaf’s life on a tree throughout autumn.

And those yellows that make you feel as if you’re walking in a ray of sunshine?

They’re produced by flavonol, which is part of the flavonoid protein family. It’s always present in leaves but doesn’t show itself until chlorophyll production begins to slow.