A northwest wind developed yesterday afternoon, behind the latest cold front, and, overnight, ushered in the coldest air and lowest wind chill since last winter. December made its appearance beneath a frigid, clear sky, lit by a crescent moon, bright Venus and a bowl of twinkling stars. On my walk to work this morning, it was 22 degrees F.

Festooned with holiday lights and leading up to the beloved season of Christmas, December does not incite the animosity that January and February stir in the soul of tropical man. Nevertheless, in the Northern Hemisphere, December is the darkest month of the year and often brings severe winter weather. Even when relatively mild, the month heralds the long, steady descent toward the nadir of nature's year.

December 1 marks the calendar and meteorologic onset of winter which, from an astronomical point of view, begins with the winter solstice, on or about December 21. One can debate when the season officially begins but, to paraphrase a Supreme Court Justice, "we know it when we feel it" and, today, it felt like winter.