WASHINGTON — Winter is coming ... later. And it's leaving ever earlier.Across the United States, the year's first freeze has been arriving further and further into the calendar, according to more than a century of measurements from weather stations nationwide.Scientists say it is yet another sign of the changing climate, and that it has good and bad consequences for the nation. There could be more fruits and vegetables — and also more allergies and pests."I'm happy about it," said Karen Duncan of Streator, Illinois.