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September 2014 Weather Recap: Dry & Warm

Sept2014calendarSeptember 2014 began and ended with significantly warmer than average temperatures.  Sept. 1-6 was 8.5 degrees above average while Sept. 26-30 was +7.5.  Meanwhile, the days in between (Sept. 7-25) were 1.5 cooler than average.  For the entire month, September was 1.7 degrees above average, with a dozen days five degrees or more above average.  This was the mildest September in three years and the 35th mildest among all Septembers since records began in 1870. 

 

 

The warm spell between Aug. 31 thru Sept. 6 was the longest stretch of warm weather all year (every day had a high of 86° or warmer) and included the hottest day of the year, Sept. 2, which had a high/low of 92/77 (thirteen degrees above average).  And the fifteen-day streak of 80-degree (or warmer) days between Aug. 24 to Sept. 7 was also the lengthiest of the year.

 

Since 1960 only September 2005 was drier than this September as just 1.21" fell.  Since records began this ranks as twelfth driest.  (Sept. 2005 is tied for second place, with just 0.48" measured.)  The "rainiest" day was on 9/25 when 0.32" was measured in Central Park.

 

No.rain

 

August and September's combined rainfall of 3.46" was five inches below average and the least to fall during these two months since 1995.  Among all years on record this two-month combo ranks eleventh.  

 

Finally, this was New York's most above average month, temperature wise, since last October (which was 3.3 degrees above average) and the driest, also since last October (which had just 0.36" of rain).

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Comparing Weather Conditions of Summer's Three Big Holidays

Previously, I've published separate posts about weather conditions over the Memorial Day and Labor Day weekends and for the 4th of July.  This post compares the three side-by-side, looking at them as single-day holidays (i.e., the Mondays of Memorial Day and Labor Day, and the 4th of July) for each year going back to 1970 (thru 2019).

 

Coney.island.crowded    

 

Because of where they fall on the calendar, you'd expect the 4th of July to be the warmest of the three holidays and Memorial Day the coolest, but that's happened in just one-third of the summers.  (On average, the high on Memorial Day is 75°, on 4th of July it's 84° and 81° on Labor Day.)  Memorial Day has actually been the warmest of the three holidays in five of the years (and tied with 4th of July in two other years) while in eleven years Labor Day was the warmest.  July 4th had the coolest temperature in six years (including 2014 and 2015).

 

YEARS IN WHICH MEMORIAL DAY WAS THE  WARMEST SUMMER HOLIDAY
         
    High Temperature
    Mem Day 4th of July Labor Day
2011   86 86 70
2009   81 79 74
2007   83 71 82
2006   88 87 75
1991   89 82 74
1985   86 86 83
1981   87 75 74
         
         
YEARS IN WHICH  4TH OF JULY WAS COOLEST SUMMER HOLIDAY
         
    Mem Day 4th of July Labor Day
2015   85 75 92
2014   86 74 88
2008   80 78 84
2007   83 71 82
1979   75 71 86
1978   79 62 80
         
     

The summer of 1999 has the distinction of having the warmest three-holiday average temperature, 10 degrees above average, while the summer of 1982 was the coolest, eight degrees below average (with 1992 close behind, at 7.5 degrees below average).

 

WARMEST 3-HOLIDAY AVERAGE TEMPERATURE
       
Summer of 1999      
  High Low Mean
Memorial Day 89 68 78.5
4th of July 96 79 87.5
Labor Day 83 74 78.5
Average 89 74 81.5
       
COOLEST 3-HOLIDAY AVERAGE TEMPERATURE
       
Summer of 1982      
  High Low Mean
Memorial Day 55 50 52.5
4th of July 77 60 68.5
Labor Day 82 60 71
Average 71 57 64
       

 

The holidays during three summers - 1972, 1986 and 2016, had nearly the same high temperatures.  In 1972 the high was 78° on Memorial Day, 79° on 4th of July and 77° on Labor Day, while in 1986 the highs were similar to 1972's, but in a different order (76-77-78).  And 2016's were all in the 80s, with a high of 82° on Memorial Day and 84° on both July 4 and Labor Day.  On the flip side, the greatest variations in high temperatures occurred in the summers of 1974 (55-95-73) and 2003 (56-92-69).

 

In the years covered by this analysis there has never been a summer in which all three holidays had highs in the 90s.  In fact, there has been only one year, 1983, in which two of the three holidays had 90-degree readings (95° on 4th of July and 91° on Labor Day).  Looking at cool temperatures, three summers saw all three holidays fail to reach 80° (1972, 1986 and 2001).

 

Eleven summers (i.e., one out of four) were rain-free across all three holidays.  The last time this happened was in 2010.  Conversely, just two years saw rain on each holiday, in 1979 and 1998.  However, in those years the three days weren't washouts nor was rain significant for each holiday.

 

Labor day weekend
  

 

 

 

 

 

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New York Weather History: September (1970 - 2020)

Backtoschool Highlights: 99° on Sept. 11, 1983; flooding rains (five inches) from tropical storm Floyd fell on Sept. 16, 1999; a tornadic storm struck parts of Brooklyn and Queens on Sept. 16, 2010; Hurricane Gloria struck Long Island on Sept. 27, 1985; the effects from tropical storm Jean moved through on Sept. 28, 2004; the first 23 days of September 2005 all had highs of 80° or warmer; September 2015 was the warmest on record; the Great Atlantic Hurricane in 1944 dumped 9.30" of rain over a three-day period.); NYC's longest heat wave on record, 12 days, came to an end on Sept. 4 1953.

 

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Today in New York Weather History: Labor Day Weekend (1970 - 2020)

Labor_day

 

On average, Labor Day weekend is about five degrees warmer than Memorial Day (high of around 80° vs. 75°).  However, hot temperatures on Labor Day itself aren't overly common.  Since 1970 the afternoon high has topped 90° just five times (most recently in 2015 and 2018).  In terms of inclement weather, chances are 2 in 5 that the entire weekend will be dry, better odds than Memorial Day weekend's 1 in 3 chance.  Tropical systems have brushed the area twice (Edouard in 1996, Ernesto in 2006).  What follows is a recap of 20 holiday weekends that had weather conditions worthy of note.

 

  • 1973 (Sept. 1-3) - This Labor Day weekend has the distinction of being the hottest of the 1970-2019 period - and the only one in which each day's high was in the 90s (95°-94°-96°).  Overall, temperatures averaged thirteen degrees above average.  Saturday's heat had a tropical component to it, which fueled late-afternoon thunderstorms that amounted to 0.25".

 

Weather_hot_sun   

 

  • 1980 (Aug. 30-Sept. 1) - This was the second hottest Labor Day weekend of the period as highs reached: 86°-90°-95°.  After a stifling low of 76° on the morning of Labor Day, the high topped out at 95°, the hottest reading for the holiday since 1973, when it was 96°.   
  • 1983 (Sept. 3-5) - Monday's high was 91°, the last Labor Day to get into the 90s until 2015 (highs in 1996 and 1998 reached 89°). 
  • 1984 (Sept. 1-3) - The weather was good all weekend until the evening of Labor Day when 1.20" of rain poured down during a thunderstorm after 8 PM.
  • 1986 (Aug. 30-Sept. 1) - Saturday's low of 51° is the chilliest reading of any day during Labor Day weekends of the 1970-2019 period.  The entire weekend was cool, with temperatures averaging eight degrees below normal.

 

Clipart_sweater

 

  • 1991 (Aug. 31-Sept. 2) - Monday's morning low of 53° tied 1976 and 1883 as the chilliest reading on Labor Day.  
  • 1994 (Sept. 3-5) - This was one of the coolest Labor Day weekends on record, with temperatures seven degrees below average.  It is also one of two Labor Day weekends between 1980-2019 in which each day's morning low was in the 50s (the other was in 1986).    
  • 1996 (Aug. 31-Sept. 2) - There was cause for concern on Saturday of Labor Day weekend when Hurricane Edouard was predicted to make landfall on Long Island.  However, the storm stayed away and the only effect from the hurricane was heavy surf, especially out in the Hamptons.  Although Sunday's conditions were somewhat overcast, Saturday and Labor Day were spectacular (Monday's high reached 89°).
  • 1998 (Sept. 5-7) - The long holiday weekend ended with severe thunderstorms on Monday afternoon and again later that night.  2.07" of rain was measured, making this the second rainiest Labor Day on record, topped only by 1926, when 2.24" fell. 

 

Clipart_severe_thstorm 

 

  • 2000 (Sept. 2-4) - Each day of the extended holiday had above average temperatures as well as a thunderstorm.  In total, these storms produced nearly two inches of rain.  In the 1980-2019 measurement period this is the only Labor Day weekend to have rain fall on each day.
  • 2002 (Aug. 31-Sept. 2) - With an average high of just 68° degrees (11 degrees below average) this is the coolest Labor Day weekend between 1970-2019.  And Labor Day itself was a washout, with 1.63" of rain falling.
  • 2003 (Aug. 30-Sept. 1) - For the second year in a row the temperature never got out of the 60s on Labor Day.  And like the previous year it rained, but not nearly as much fell (0.59"). 
  • 2006 (Sept. 2-4) - The extended weekend started off cool and wet as tropical storm Ernesto moved through, dropping 1.24" of rain; the day's high was just 66°, thirteen degrees below average.  Sunday and Monday, however, were very nice, but cooler than average (mid-70s). 
  • 2011 (Sept. 3-5) - This was the eighth year in a row in which no rain fell on Labor Day, the longest such streak since one of ten years between 1958-1967.  This was also the mildest three-day weekend since 1983, five degrees warmer than average. 

 

Clipart_pleasantsun

  • 2012 (Sept 1-3) - After a sunny and hot Saturday (the high of 91° was the first 90-degree reading during Labor Day weekend since 1998), Sunday and Monday were overcast - but Labor Day's dry streak continued.  The three-day weekend's mean temperature was six degrees warmer than average, the most above average LD since 1983.      
  • 2013 (Aug 31-Sept 2) - Conditions all weekend were sultry with hazy sunshine and uncomfortable levels of humidity.  Scattered thunderstorms occurred throughout the area on every day, but Manhattan was spared until Monday afternoon when rain fell for a few hours - the first rain to fall on Labor Day in ten years.  The overnight hours were especially warm, with AM lows of 73°-75°-74° averaging nine degrees above average.  However, the diurnal variation was just ten degrees. 
  • 2014 (Aug. 30-Sept 1) - This was the warmest Labor Day weekend since 1983 (and fourth warmest since 1970).  The weekend started out mostly overcast with seasonable temperatures (high/low of 80°/65°) but hot and humid air moved in overnight and Sunday and Monday saw highs/lows of 90°/73° and 88°/75°.  On Sunday a half-hour downpour late in the afternoon dumped 0.62" of rain.
  • 2015 (Sept. 5-7) - Sunny and warm throughout with each day warmer than the next (highs of 83°-87°-92°).  Labor Day's high was the first in the 90s since 1983.
  • 2016 (Sept. 3-5) - It was a rain-free weekend, with highs of 75° on Saturday, 80° on Sunday and 84° on Labor Day - which was the same high as 4th of July (and Memorial Day wasn't far behind, with a high of 82°).  It was a nice surprise that the holiday weekend ended up being so nice since earlier forecasts predicted tropical storm Hermine would stall off the Mid-Atlantic on Sunday and Monday, but it moved further east and posed no threat.  
  • 2017 (Sept. 2-4) - After a cool and mostly overcast Saturday and Sunday (which included 1.27" of rain on Saturday evening thru early Sunday AM), Labor Day turned out beautiful, with mostly clear skies and seasonable temperatures.  All told, this was the coolest Labor Day weekend since 2004).
  • 2018 (Sept. 1-3) - After close to seasonable temperatures on Saturday and Sunday, Labor Day featured summertime heat, with a high/low of 90°/75°.
  • 2020 (Sept. 5-7) - Cookie cutter conditions prevailed as each day of the extended weekend was sunny, with comfortable humidity and temperatures that were slightly above average (+2 degrees).  Each day had very similar highs/lows: 80°/65° (Saturday), 82°/66° (Sunday), and 79°/66° (Labor Day).

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Warm September Mornings in New York

Clipart_suntapping_onwindow

 

Average low temperatures in New York during September range between 64° at the start of the month to 56° by the 30th, but a typical September will see three days with daily lows of 70° or milder (the average in the years since 2010 has risen to five).  Since 1869, the September with the most days with lows in the 70s is September 1961 - twelve.  At the other end of the spectrum there have been 33 years with no 70-degree lows (about once every four or five years), with the most recent being in 2009.  What follows are additional facts about warm September mornings:

 

  • After 1961's twelve days with lows in the 70s, 1971 follows with eleven and 1959 reported ten such days.  September 1884 had the most consecutive days with lows in the 70s, eight, which occurred between Sept. 4-11.  More recently, September 1979 had a streak of seven days in a row.  The greatest number of 70-degree lows in consecutive years occurred in from 1905 to 1907 when there were eight, seven and nine, respectively.
  • The warmest daily minimum in September is 79°, which happened twice, first on Sept. 7, 1881 and a second time on Sept. 2, 1898.  Lows of 78° have occurred five times: on Sept. 3 and 4 in 1898; Sept. 11, 1983; Sept. 6, 1985; and most recently on Sept. 2, 2010. 
  • The coolest low temperature to be the mildest of any September is 64°, which occurred in 1917 and 1935.
  • There has been one three-year period with no 70-degree lows in September, 1962 to 1964.  The longest streak of Septembers with lows in the 70s lasted twenty-three years between 1894 and 1916.  We're currently in the midst of an eleven-year streak (2010-2020), with every September except for 2019 and 2020 having four or more lows in the 70s.
  • Although only six of the days had 70-degree lows, September 2018 established a new record with 17 days with lows of 67° degrees or warmer (the average number of such days is six).

 

70s 2
 

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Looking Back at New York Weather: September 30

 

1871

Today's high was 61°, the eighth day since 9/14 with a high in the 56°-62° range (the average high during this time of September is in the 70°-73° range).  These unseasonably cool days helped September 1871 become the coolest September on record (a distinction that still stands).

1884

The last three days of the month accounted for all of September's rain, and it was very little - 0.21", making this the driest September on record (a dubious honor that it still holds).

1921

This September stands out for being the only one that was warmer than August.  In keeping with the warm conditions, today's high was 87°, then a severe thunderstorm between 5:00 and 6:00 dumped a little more than an inch of rain and winds gusted to 40 mph. 

1948

Until today, when 0.70" of rain fell, just 0.53" of rain had fallen during the month.  Today's amount was more than what fell in the previous six weeks. 

1959

The unseasonably warm temperatures of August (at the time the fifth hottest on record) continued in September, which tied September 1931 as the second warmest (it's now tied for fifth).  The month's temperatures were divided into three ten-day periods.  The first ten days were eight degrees above average, the middle ten were six below average, and the last ten days were nine above average.  Today, with a high of 82°/70°, was twelve degrees above average; the low was what the average high typically is.

 

New yorker sept 1959  

1983

Rain from the remnants of tropical storm Dean moved through during the early morning.  2.64" fell between 4-9 AM, but the bulk of it poured down in the hour between 7:30-8:30, when 2.05" was measured.  Today's rainfall was comparable to the amount that fell between Sept. 1-29.

1986

Today's summer-like high of 89° was 20 degrees above average and a record for the date.

Clipart_sizzlingsun1992

For the second year in a row the chilliest reading of September occurred on the final day of the month, and in both years the reading was 44° (12 degrees below average).  However, this year's high, 58°, was five degrees chillier.

2001

Today's high of 55° was 15 degrees chillier than average.  It was also the last time until September 2016 that a day in September had a high in the 50s.

2005

Today's high/low of 67°/50° made this the only day of the month that a had cooler than average mean temperature (four degrees below the norm).  Not only was this the second mildest September on record (now tied for third), but the fourth driest (0.48 inches was measured).

 

Clipart_sunimage 

2010

0.75" of rain fell in a 45-minute period just before daybreak (6-6:45 AM).  Overall, 1.10" fell during the morning.  This followed a rainstorm on 9/27-28 that dropped 1.66".  These two rain events accounted for 75% of September's rainfall.

2016

It was a gray day, with persistent drizzle and winds out of the northeast.  These conditions kept the temperature in the upper 50s all day.  The high of 59° (eleven degrees below average) was the first high in the 50s in September in fifteen years.

 

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Today in New York City Weather History: September 29

 

1959

The 0.02" of rain that fell shortly after midnight from a storm that began late last night (and dropped 0.34" from 11 PM-midnight) was the first measurable rainfall on this date since 1936.  At the time, this 22-year streak with no rain was the lengthiest on record for a calendar date, later passed by a 25-year streak on Dec. 1 for the years 1943-1967.    

1974

In its fifth year, this was the first New York City Marathon to see rain as thundershowers produced 0.32" of rain between 3-4 PM and 0.10" between 5-6 PM (but well after the leading runners had crossed the finish line).  It was also a warm day, with a start-time temperature of 74°.

 

Nycmarathon tshirt

1979

The morning low was a summer-like 71°, fifteen degrees above average.  This was the latest for a low in the 70s since 1959 (when it occurred on 10/1), and would be the latest date until 2005, when that year's last 70-degree low temperature fell on 10/7 (and then 2010's occurred on 9/28; 2015's on 9/29; 2017 had 70-degree lows on 10/8 and 10/9; and in 2018 it was on 10/10.)  The average date for the occurrence is Sept. 11.

1996

The 0.18" of rain the fell between 2-5 AM was the first rain on this date in seventeen years.

2000

The morning low of 43° was the chilliest reading in September since 1963.

 

Autumn_leavesl 

 

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Today in New York Weather History: September 28

 

Since 1970, Sept. 28 is the average date of the last 80-degree day of the year.  It's occurred as early as Sept. 10 (in 1996) and as late as Nov. 15 (in 1993).  This is one month after the average date of the last reading of 90°+ (Aug. 28).

 

1975

The sixth NYC Marathon was held today and participants breathed a sigh of relief as the City dried out from a string of rainy days that produced 8.50" over eight consecutive days, ending Friday.  This included an unprecedented four days in row in which more than an inch of rain fell.  Today, however, was sunny with near seasonable temperatures (high/low of 69°/57°). 

1977

This was the seventh day in a row in which some rain fell.  Today's amount was just 0.03", which fell between 3-4 AM.  (The first day of this streak also had 0.03".)  In total, three inches of rain fell during the seven days.  

1984

The month's temperature extremes occurred three days apart as this morning's low of 44° followed a high of 86° on 9/25.

2004

Three weeks after the remnants of Frances and ten days after Ivan, the remnants of a third tropical system, Hurricane Jeanne, moved through.  By the time its rain ended the following morning, 4.66" had fallen, the most from a storm since tropical storm Floyd dumped 5.44" in 1999.  The rain that fell today, 3.84", was a record for the date and brought the month's total to 11.41" making this the rainiest September since 1934.

 

Track_of_hurricanej_eanne

 

2010

After a sultry morning low of 70° (fourteen degrees above average), the temperature rose only three more degrees the rest of the day.  This was the 55th, and last, day this year with a low of 70°+, which was 50% above average and the third greatest number of days on record (now tied for fifth place).

 

Chart - most lows of 70+
2011

For the past seven days the morning lows were between 68° and 70°, twelve degrees above average and more typical of mid-August.  High temperatures during these days averaged 77°, five above average.

2012

Torrential downpours through mid-afternoon amounted to 1.96", much of which fell in a two-hour period between 9:20-11:20 AM.  This was the second day this month with more than an inch of rain (1.54" fell on 9/18) and the first month with two such rain events of this magnitude since last October.  Additionally, this was the seventh year in a row, and tenth of the past eleven, in which rain fell on this date.

Clipart_master_dog_rain

2014

The last weekend of the month had spectacular weather.  Under clear skies on Saturday and sunny skies on Sunday, high temperatures rose into the low 80s, thirteen degrees above average.  (And Friday was equally fine, with clear skies and a high in the upper 70s.)

2018

The 0.77" of rain that fell this morning pushed September's total rainfall past six inches, making this the third month in a row with six inches or more.  This became just the ninth such streak on record (going back to 1869), all of which have occurred since 1971.

 

Chart - 3 months 6 inches+ precip

 


 

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Today in New York Weather History: September 27

 

1908

This was the 21st day in a row with no rain.  (The other nine days of the month had rain on three days, which amounted to 1.91".)

1975

Although it amounted to just 0.02", the rain that fell shortly before daybreak made this the ninth day in a row in which some rain fell.  (The first day of this streak also received 0.02").  In total, 8.95" of rain fell, most of it coming during four days in a row (Sept. 23-26) that each had more than an inch of rain. 

1985

Hurricane Gloria made landfall on Long Island near the Nassau/Suffolk border and dumped heavy rain in the City during the morning (3.13", a record for the date), with most falling between 9:30 AM-12:30 PM.  Skies cleared around 1:00 and the rest of the afternoon was beautiful.  The bountiful rain helped put a dent in the year's rainfall deficit.  (To read my first-person account of the storm double click here.)

 

Hurricane_gloria

1998

Today's high of 89°/low of 69° was 15 degrees warmer than a typical day in late September.

2010

1.33" rain fell throughout the day, exceeding the total amount that fell in the previous four weeks.  One year earlier 1.03" fell on this date.

 

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Today in New York Weather History: September 26

 

1940

Clear skies and very chilly, with a high/low of 60°/42°, which made it feel more like early November.  The morning low, 15 degrees below average, was a record for the date (which still stands).  This chilly air followed a rainstorm that swept through yesterday morning, dumping more than two inches of rain (a record for the date that also still stands).  This accounted for almost all of September's rainfall. 

1970

Between Sept. 22 and today, four of the days had afternoon highs in the 90s: 94°-93°-87°-90°-91° (today).  Furthermore, all five days had mean temperatures that were fifteen degrees or more warmer than average.  Yesterday and today's highs were records for the dates; today's was the latest 90-degree reading since 1941.  

1975

For the fourth day in a row, more than an inch of rain fell.  At the onset of this deluge rain fell for 47 consecutive hours.  Total rain during these four days amounted to 7.43".  (1.82" fell today; 1.05" yesterday; 2.26" on 9/24 and 2.30" on 9/23). 

 

Weather.downpour on umbrella 

1993

Beginning at 11 PM last night and continuing through 10:00 this morning 1.66" of rain fell.  It came down heaviest this morning when an inch fell between 6:45-8:45 AM.

1995

This was the seventh year in a row that rain fell on this date.  The 0.42" that fell today occurred throughout the day.

2005

Evening showers amounted to 0.17", the "rainiest" day of what turned out to be the driest September since 1884.  By contrast, September 2004 had 11.51" of rain, the wettest since 1934.

2007

Today's high was a sultry 87°, fourteen degrees warmer than average.

2008

The morning was very soggy as heavy rain amounted to 2.34", most of which fell between 3-10 AM.  This was a record rainfall for the date.

 

Morning_rainstorm

 

2018

A new September record was set as the day's low of 69° was the seventeenth this month that was 67° or warmer, breaking a tie with 1971.  (A typical September has six days with lows this mild.)

2020

This was the sixteenth day in a row with no measurable rain, one day more than June's dry streak, which had been the longest this year.  The last time there was a lengthier streak was during the fall of 2017 when there was one of eighteen days (Sept. 20-Oct. 7). 

16 days

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