December is the birth of a new season; another new beginning.We recognize December 21 as the winter solstice, the shortest day of the year.Whatís interesting, however, is that, even thought December 21 is, in fact, the day with the shortest daylight, it is not the day of the earliest sunset or the latest sunrise.The earliest sunsets in our DC area occur at 4:46 from December 2 through December 12.This, combined with the latest sunrises, which occur nearly a month later, at 7:27 from December 30 through January 10, makes the shortest day a compromise between these two extremes.


Itís also worth noting that the earth is closest to the sun at this approximate time in its annual ecliptic path around the sun (actually, it reaches its closest, or perihelion, on January 3).So, why is it at itís coldest at this time?Itís the tilt of the earthís axis away from the sun in the northern hemisphere (23į) and the resultant acute angle of the sunís rays that more than compensates for the nearness of the sun (a mere 3 million miles closer).For the same reasons, our warmest time of the year occurs when we are at the greatest distance from the sun (aphelion is reached on July 4).No wonder the hottest and coldest places in the world are found in the southern hemisphere where these two conditions work in tandem to create the temperature extremes.


From this day throughout the next six months, total day length will be increasing. Solar radiation, the ultimate source of all life on earth, will slowly halt the momentum of the cooling environment and turn us back towards the warmth of another growing season.It takes a while for the sunís warmth to take effect.In fact, our daily temperatures will continue to decrease until January 8 through 23, where the average bottoms out at 42į(Again, the same lag time applies to our warmest day, which tops out at 89į from July 16 through 27; a month after the longest day.)


It is the first day of the new year for me.The first positive Ďlightí that spring is on its way.