It’s still too early to say how brilliant fall foliage season will be this year — but months of wet weather could delay its inevitable arrival.
Fall weather, especially temperature and wind, largely determines how brilliant foliage becomes each autumn. But in some years, spring and summer conditions also have some influence.
In dry weather, trees are stressed, causing leaves to turn brown and drop earlier than they might otherwise, for example. Given the abundance of rain so far this year, on the other hand, trees are healthier, according to the Foliage Network, which tracks leaf change across the country.
“That might delay the change slightly,” said Marek Rzonca, who organizes the network.
A late arrival of spring, like this year’s, can delay leaf change, too, according to the group.
And continuing warm weather could stall the appearance of bright reds, yellows and oranges. Seasonably cool early fall temperatures trigger leaf change, but that sort of a chill has been rare so far this season.
Extended warmth during early fall can dull the brightness of leaf colors, the Foliage Network says.
September was Baltimore’s 10th warmest on record, and after brief cool spells last weekend and Friday, temperatures are expected to rise into the 80s this weekend and into next week.
“The combination of very warm weather and abundant rain should lead to a later foliage season,” Rzonca said.
According to the network’s latest report, low levels of color were appearing along the mountains of Western Maryland, West Virginia and Virginia. Those regions usually become most colorful in the last week or two of October.
Otherwise, no significant leaf change or drop is occurring in the region.
Peak color typically doesn’t arrive in Central Maryland until the very end of October or in the first week or two of November.
How long color sticks around is difficult to predict because it also depends on the weather — strong winds or heavy rain can cause leaves to drop more quickly.
“Ideal foliage is produced by a warm and wet spring, typical summer conditions, and mild, sunny autumn days with cool evenings,” the group says.