The DNR says scant recent rainfall threatens to dim the fall colors in some areas.
The Brown County State Park naturalist says he expects the peak to be in late October, but people are already flocking to the area to see the color change.
Watch a video of the color change in Brown County, which is at its peak this week.
A naturalist at McCormick's Creek State Park says temperature is always the key factor in how colorful the leaf show will be.
Brown County tourism officials must make a guess and do some math to ensure peak revenue from the county's famous fall foliage.