Since 1970 the average date of the first measurable snow in New York's Central Park is Dec. 15, with the two weeks between Dec. 5 and Dec. 19 being the "sweet spot"; however, in ten years it happened in October/November (most recently in 2018), while in eight winters it didn't occur until January (most recently, in the winter of 2015-16). The earliest measurable snow (since 1970) fell on Oct. 29, 2011 while the latest was Jan. 29, 1973.
After mild temperatures in the overnight hours, and a hard rain in the morning that amounted to 1.16", the temperature plummeted from 60° to 22 °.
This was the last day this month with a high above 40°. (The next time the high reached 40°+ would be on Jan. 2.)
A snowstorm dumped 12.7" of snow between 7 AM-9 PM, with nearly ten inches on the ground by mid-afternoon. The snow was very fluffy, produced from just 0.59" of water (and by daybreak on 12/16 the amount on the ground had packed down to nine inches on the ground). The day's high was 28°, the first of five days in a row with highs in the 20s.
A storm that moved in yesterday, with rain in the late morning, saw a change over to snow just after midnight today as the temperature dropped from mid-30s to the low 20s. 5.2" accumulated by 12:00 noon.
0.3" of snow fell overnight, the first measurable snow of the winter. However, it was all gone by early afternoon as the temperature rose into the upper 30s. Today's precipitation was the first to fall on this date since 1958.
For the first time this winter the high temperature remained below freezing all day (high of 31°/low of 18°). And the first snowfall of the winter arrived after 9 PM, accumulating 1.1" by midnight.
This was the thirteenth day in a row with a high colder than 40°. The average high/low during this nearly two-week period was 34°/25°, ten degrees colder than average. Today's high/low of 38°/18° followed yesterday's 24°/14° (which would be the coldest day of the winter).
Today's high temperature of 67° was a record for the date, twenty-four degrees above average. This was one of seven days between Dec. 9 and Dec. 28 with a high of 57° or warmer (three days were 65°+). This was also the third year in a row to have 0.01" of precipitation fall on this date.
For the sixth day in a row temperatures were in the 60s - and today was the mildest of them all, with a high of 68° reached in the wee hours of the morning. The only longer streak of 60°+ in December was one of seven days in 1998 during the first week of the month. Today was the third day in a row with a record high, and the fourth day in a row with a record-mild low temperature.
With a high/low of 28°/20° today was the third day in a row with a high of 32° or colder, the longest such streak in December in seven years. And during the afternoon/early evening 1.2" of snow fell, the third day in the past seven with a snowfall of an inch or more (joining 4.6" that fell on 12/9 and 1.2" on 12/14).