It was a very mild winter in most of the Northeast United States, and the record warm temperatures of the past few weeks have a lot of plants behaving more like it's mid-April, not mid March. Daffodils are blooming, hyacinths and showing color in their buds, and fruit trees are already blossoming in some areas.
This article describes the anxiety some orchardists are feeling about the weather, and how vulnerable trees are. A late frost can kill blossoms and wipe out an entire crop. I've seen this happen in western New York more than once, where the wild apple trees of the Brushwood Folklore Center went two years with practically no fruit.
There is little orchardists can to to protect their trees in this situation. With Northeast winters seemingly becoming milder every year, will this mean problems for orchards and fruit growers? It is a worrying trend.