« November 2013 | Main | January 2014 »

December 2013

New York's Top 10 Weather Stories of 2013

 2013_review

 

Although 2013 didn't have a headline grabbing weather story like 2012, when Sandy pounded the area; or 2011, which was the wettest year on record; or 2010, with its record hot summer and two 20-inch snowstorms, this year set a number of records for warm low temperatures.  Additionally, it had two extended periods of extreme precipitation, one wet, the other dry.  Here are the ten or so most noteworthy events:

 

  • The coldest temperature of the year, 11 degrees, occurred on Jan. 23 - the coldest reading in two years.  The hottest temperature of the year occurred the afternoon of July 18 when the high reached 98 degrees.  This was the same day as 2012's hottest temperature (when it hit 100).
  • On Feb. 8-9 a snowstorm dumped 11.4".  As much as this was, the City escaped the 20-30 inches that fell in parts of Long Island and southern New England.  This was New Yrk's twelfth snowstorm of ten inches or more since 2000.

 

Snowy_7thavesouth

 

  • March's coldest temperature was 27 degrees, which was the mildest minimum temperature in March since 1973, when the coldest reading was 30 degrees.
  • In a little less than two months (May 8 - July 3) 19.55" of rain poured down in the City.  Then in the fall there was a 60-day stretch (Sept. 23 - Nov. 20) in which less than an inch of rain fell - the third longest such streak since 1950.  These two periods more or less cancelled each other out as the year ended up somewhat below average in precipitation.
  • The three-day Memorial Day weekend was the second chilliest since Memorial Day became a Monday holiday in 1971.  Saturday was especially chilly, with a high/low of only 54/45. 
  • On June 7-8 tropical storm Andrea dumped 4.77" of rain over 33 hours.  This was the second earliest tropical system on record to affect the New York metro area.
  • A seven-day heat wave between July 14-20 was the longest in 11 years.  It has the distinction of having the warmest mean temperature of any heat wave of seven days or more.  Very sultry low temperatures were responsible as there were eight days in a row between July 16-22 with morning lows of 75 degrees or warmer, another record.

 

Weather_hot_sun  

 

  • Just 0.36" of rain fell in October, making it the driest month since August 1995.
  • in a 10-day period between Dec. 8-17 temperatures were eight degrees below average and 8.6" of snow fell from four snow "events".
  • The temperature soared to 71 degrees on Dec. 22 - just the ninth time a 70-degree reading occurred in December.  Furthermore, the day's low of 61 was the mildest low temperature in December on record.  Then three days later the mercury dropped to 19 degrees, making this the area's coldest Christmas Day since 2000. 

 

Arrows_up_down_arrows

 


A History of Mild December Temperatures in New York

Clipart_meltingsnowglobe

 

 

  • Since 1970 the warmest reading in December has averaged 60°.  Between 1970-1999 it was 58°; since 2000 it has been 64°.
  • December 1998 and 2001 each had two days with 70-degree highs. And every day of the first week of December 1998 had highs of 60° or warmer (including the two 70-degree highs).
  • In eleven years since 1970 the mildest reading in December has occurred after the first day of winter.
  • Since 1970 six years have had mildest December readings of 55° or lower.  The coolest maximum was 53° in 1989.
  • In 2004, 2005, 2006 and 2015, December's mildest reading occurred just before Christmas (12/23, 12/24, 12/23 and 12/24, respectively).
  • December 2013 is just one of four Decembers since 1970 that had a warmer reading than November.  The other three were in 2006, 1998 and 1983.   
  • Decembers with very mild readings don't preclude significant snowfalls.  For example, 2013's 71-degree reading on 12/22 followed a wintry 10-day period between 12/8-17 which saw 8.6" of snow.  In 1984 a 70-degree day on 12/29 came just two days after 4.8" of snow fell; in 1990 a snowfall of 7.2" came five days after a high of 66° on 12/23; and in 2008 a 4.5" snow event followed a high of 67° five days earlier on 12/15.

 

Clipart_tropical_santa  

 70 in December

 

December Chilliest Max

Save

Save


A History of New York's First Snowfalls of the Winter

Weather_snowlined_trees_centralpark

 

Since 1970 the average date of New York's first measurable snowfall has been December 14 (six days later than the 30-year period before that, 1940-1969).  It has occurred as early as Oct. 29 (in 2011) and as late as Jan. 29 (in 1973).  It has happened before Dec. 1 in seven years (including the winter of 2018-19) and occurred later than Jan. 1 fifteen times (including the winter of 2015-16).  When this first snow arrives, on average, it's accumulated two inches. 

 

In two out of five winters the first snowfall amounts to less than an inch; five had first snowfalls that measured just 0.1" (the last time was in 2010).  On the flip side, there have been nine winters with first snowfalls that accumulated more than four inches (most recently, the 10.5" snowstorm of Dec. 16-17, 2020, the surprise 6.4" snowstorm on Nov. 15, 2018, and a 4.6" snowfall on Dec. 9, 2017).  The greatest amount for a first snowfall was 15.2" on Dec. 11-12, 1960.

 

Chart - biggesst first snowfalls



The average date of the first snowfall of 1-inch+ occurs on Dec. 24, ten days after the first measurable snow (and eight days later than the years between 1940-1969).  It's happened as early as Oct. 29 (in 2012 when 2.9" fell) and as late as March 22 (in 1998 when 5.0 inches fell).  Ten winters didn't see their first one-inch snowfall until after Jan. 15.  The last time it occurred this late was during the winter of 2015-16, and it was a doozy, when 27.5" fell on 1/22 - New York's biggest snowfall of all time.

 

Weather_timessquaresnow

 

Finally, the first measurable snowfall of the 50 winters since 1970 was also the the first snowfall of an inch or more 27 times (most recently during the winters of 2019-20 and 2020-21).  Additionally, eight of the first snowfalls changed to rain; four of them occurred in consecutive winters, 1984-1987.  And seven of the first snowfalls began as rain before changing to snow (the most recent was the winter of 2019-20).

 

Weather-snowfalkes

 

 

    

Save

Save

Save

Save

Save

Save

Save

Save

Save

Save


Longest Periods of Time With Less Than an Inch of Rain in New York City

60Days

 

In the fall of 2013 New York experienced a 60-day stretch in which just 0.95" of rain fell (beginning Sept. 23 and lasting thru Nov. 21).  Since 1950 this was the third longest streak with less than an inch of total rainfall, ranking behind one of 81 days in the summer of 1999 and one of 61 days in the summer of 1964.  (Since 1900 New York has had more than 50 months with less than an inch of rain.  However, there have been nearly three times as many 30-day periods with less than an inch that have crossed months.)

 

 

Dry Weather_singin_in_rain2013's long stretch of dry conditions came four months after a near-record period of wet weather in May and June that saw rainfall of 18 inches in just seven weeks.  These two extremes in precipitation may very well balance each other out and result in the year's total precipitation being not far from average (the year would end up with 46 inches, about four inches below average).  And lengthy dry periods don't always mean that the entire year will have below average precipitation.  For example, 2005 and 2006 both had seven-week periods with less than an inch of rain but their total precipitation was well above average (56 and 60 inches, respectively).

 

Chart - Less than 1 Inch of Precip