The last time there was a 90-degree day in October was 1900. There have been 10 days in October that reached 90 degrees before this year, and all happened between 1897 and 1900, according to National Weather Service data examined by the Journal-News.
The heat this late in the season is combining with the months-long drought to cause some trees to drop leaves early and others to delay the turn to fall colors, said Tyler Stevenson, a forester with Ohio Department of Natural Resources.
Usually leaves would begin turning and falling in mid-October, but many trees won’t turn until late October or November.
“Mild drought is good for the bright reds and purples, but when you get to much more of a lack of rain, it definitely affects those colors not being as bright,” Stevenson said. “Those reds won’t pop as much if the drought continues.”
The colors will be impacted in urban areas with landscape trees and trees on the edge of forests that get more sun and have more compacted soil from foot traffic or parking beneath them. Those trees have bigger issues gathering water during drought conditions than untouched soil in forests that are more like sponges, he said.
The leaves on some landscape trees that are significantly stressed by drought conditions are browning and falling off, but for the leaves that aren’t dying, the turn will take longer. While urban trees will struggle, forest and park trees will still turn later this year.
“You’ll find fall color this year. You’re just going to have to go look for it,” Stevenson said.
Miami Valley homeowners with trees should give them some water, especially trees that were planted in the last several years and are still trying to get established, Stevenson said. Trees also shouldn’t have turf or mulch straight up to the trunk. Mulch is good for holding in moisture, but it should be 2 to 3 inches from the base.
Trees should get some relief Thursday when a cold front flows into the Miami Valley, dropping the high to 69 by Friday, bringing what Jones said he expects to be the end to 90-degree days for 2019. But the light showers won’t make up for the drought’s 6- to 8-inch deficit.
The start to October is expected to challenge several records, including one set in 1897, a year that also faced severe drought conditions in September. The Oct. 1 record was established at 93 degrees that year, which today’s 92-degree forecast could contend with. Wednesday’s 90-degree forecast could tie the record for that day, set in 1900.
Usually around this time, when fall runners hit the trails and football teams play Homecoming games, temperatures hover in the 70s. People taking advantage of outdoor activities need to take into account summer heat best practices during the start of this week, Jones said.