“We’ve had years where we suddenly have a heat wave and the trees can go into full blossom pretty much overnight, and then five days later they’re losing their petals,” she added. “If a tree blooms and then we have something like we’re having now, where the weather goes back to cooler weather, it kind of refrigerates the trees and preserves the blossoms for people to enjoy for longer,” Ms. Peters said, but having a bit of cold weather after first bloom can make the flowers last longer. The earliest trees usually start blooming when there’s a stretch of 60-degree days, Ms. “It’s not like we’re waiting for that moment where the largest number of trees are blooming, because each moment is special.”

“Every time a friend asks me about CherryWatch, like, ‘Oh, when is peak bloom,’ I don’t like that question,” she said. Elizabeth Peters, the director of digital media at the Brooklyn Botanic Garden, said that her team updates its CherryWatch tracker by checking each cherry tree in the morning to determine whether it’s in prebloom, first bloom (when about 10 percent of its flowers are open), peak bloom (when about half of its flowers are open) or post-peak bloom (when about 10 percent of the blooms are left).

Cherry blossom doodle