The beginning of spring depends on how you define the season. Astronomically speaking, spring begins two weeks from today, when the Sun will be directly overhead at the equator. If you are into accounting spring began on March 1st. By convention, official weather records consider the three months of March-May as spring in the Northern Hemisphere. This is solely to make climate comparisons between years and locations possible. More organically, spring is when temperatures begin to rise and cyclonic activity, or storminess, begins to decrease. On average winter temperatures in New York bottom out in mid-January, slowly rise through February before taking off in early-March.
This winter has confounded all expectations. Temperatures actually began increasing in mid-December before slipping back to wintry levels two weeks ago. The almost total lack of winter is difficult to comprehend. Gothamist calculated this morning that 2006's temperature is running 4.3 degrees above normal. This is stunning. The warmest years on record, 1990, 1991 and 1998 were only 2.1 degrees above normal. If the weather continues its warm ways for the rest of the year (admittedly it is still very early in the year) the city's annual average temperature record will be shattered. It would be the weather equivalent of Jamaica, Queens native Bob Beamon's 1968 long jump record, which Infoplease says defies "all reasonable comprehension".
We've got mostly pleasant weather on tap for the remainder of the week. A shower or two may sneak by on Thursday. Temperatures will gradually rise each day through Thursday. A warm front on Thursday night will push us into the 60s Friday and Saturday before falling again to the well above normal mid-50s on Sunday.
Infrared GOES image from the National Weather Service