Marc Abrams, a Penn State professor and forest ecologist, has been watching the leaves change colors for 28 years, and in the early going this year he has noticed a change of another sort.
"We often times get some early color," he said, "and there seems to be more this year."
We've noticed sporadic media reports of early color changing, and already we've seen some dramatic color in New England.
Abrams believes the generally cool and wet summer weather has been a factor.
Although around here, temperatures for the meteorological summer -- June 1-Aug. 31 –were a hair below normal and precipitation a few splashes below, as a whole the Northeast was quite wet and cool.
In the 118 period of record, this was the Northeast's second-wettest in the 118-year period of record, according to the National Climatic Data Center, and No. 21 for coolness.
Abrams says that was tonic for the trees and an ideal warm-up for the foliage season. Now he is rooting for some dry weather with cool, but not freezing, nights, conditions that tend to promote strong colors.
"The ideal conditions would be for things to start to dry out and cool down," he said. "I'm not worried about the cool-down part, but I'd like to see it dry out."
All that said, neither Abrams nor anyone else has figured out how to forecast the intensity of colors or to pinpoint timing.
Leaf-change is driven primarily by changes in sunlight, which are constant year-to-year. However, in ways not entirely understood, meteorological conditions are factors in year-to-year variations of onset and intensity.
"It's not really a hard science," said Abrams. "We don't really study it scientifically … because there isn't the money."
Foliage color isn't considered a pressing social issue, but Abrams argues that it is of some economic importance in the Northeast, which hosts some of the world's most-spectacular leaf colors.