At the National Arboretum, the white petals of snowdrops - normally an early spring flower - have unfurled. In Maine’s Acadia National Park, lakes still have patches of open water instead of being frozen solid. And in Donna Izlar’s back yard in downtown Atlanta, the apricot tree has started blooming.

It’s not in your imagination. The unusually mild temperatures across several regions of the country in the past few months are disrupting the natural cycles that define the winter landscape.