Where I lived as a child, in northern Maine, USA, we could expect deep snow and very cold temperatures every winter, with snow falling as early as October, and as late as May. It was a subarctic climate. Now, northern Maine experiences mercurial weather patterns, becoming warmer throughout the year, with less snow cover over the winters. Thirty years ago, my mother called me at Christmas, when I was living in the mid-Atlantic region. “There’s no snow,” she said. “I’ve never seen that. Even old Mrs. Vance can’t remember an open winter. You know what they say – a green Christmas means a full graveyard.” I don’t know if that proverb had any basis in fact, but it does signify how unusual, and dangerous, a warm winter was in the collective memory.