September Feed

90-Degree Days in September



September is more likely than May to see 90-degree temperatures.  While May experiences a 90-degree day once every three years, September sees one about every two years.  The most such days in occurred in 1961, when there were eight, followed by seven in 1895, 1970 and 1983.  The most consecutive years to have a 90-degree reading in September is eleven, from 1936 to 1946.  (More recently, there was a seven-year streak between 2012-2018.)  The most consecutive years without one is six, from 1885 to 1890.  Finally, three days in September have never had a reading in the 90s: 9/28, 9/29 and 9/30 (9/24 was on this list until 2017). 


Only four of New York's ten warmest Septembers are among those with the most days in the 90s: 2015 (warmest September on record/six 90-degree days); 1961 (second warmest September/eight 90-degree days); 1931 (sixth warmest/five 90-degree days); and 1983 (tenth warmest/seven 90-degree days).  And one of the ten years with the most 90-degree days, 1988 (32 days), reported no 90-degree days in September.




Finally, there have been five years with 90-degree readings in October - four were concentrated between 1938-1941, and the last time was in 2019.  Two of those years were back-to-back (1938 and 1939), and in both years there were no 90-degree days in September.  October 1941 had two 90-degree days, including the hottest October reading on record - 94° on 10/6.  In addition, there have been nine  years in which there were 90-degree days in the last ten days of September, most recently in 1980.


Most 90 Degree Days in September



The 'Last Gasp' of Summer - Noteworthy Late Summer Warm Spells



Late season heat waves can be great if your vacation happens to coincide with one of them, or if it occurs over the Labor Day weekend.  However, they can also be unwelcome, especially in years when a hot summer doesn't want to let go of its grip (as was the case in 1980, 1983, 1993 and 2010).  Since 1940 there have been more than two dozen of these last gasps of summer (of at least five days).  Some are distinguished by temperature, others by number of days.  For this analysis I discuss seventeen I found to be of greatest interest. (By "late season" I'm referring to any unseasonably warm spell that occurred between Aug. 20 thru about Sept. 20.) 


1947 (Aug. 22-26 and Sept. 7-15)

1947 is the only summer in this analysis with two late warm spells.  The first had an average high of 91°, which was nine degrees above average; the second's average high of 86° was ten degrees above average.  

1948 (Aug. 25-30)

This six-day sizzler merits attention because three of the days had highs in the triple digits and two others had highs of 95°.  With an average high/low of 97/76 this is the hottest of the late summer heat waves.

1953 (Aug. 24 - Sept. 5)

This one is the stand-out of all the late season hot spells - all twelve days were in the 90s, including six in a row with highs of 97° or hotter (two of which were in the triple digits).  This is also the longest heat wave in NYC history.

1959 (Aug. 25 - Sept. 9)

This sixteen-day stretch followed an eleven-day hot spell between Aug. 12-22 that ended when two days had unseasonably cool highs in the low 70s.  Then the heat returned beginning 8/25 and continued for sixteen days.  And there would be an early autumn warm streak of nineteen days from Sept. 22 thru Oct. 9.

1961 (Aug. 25 - Sept. 14) & 1964 (Aug. 22 - Sept. 11)

These two are grouped together because they were very similar.  Both lasted for 21 days, the lengthiest of any of the late summer warm spells.  And both had very similar dates.  1961's was a bit hotter than 1964's, with an average high/low of 89/71 versus 87/65; 1961 had nine 90-degree days while 1964 had seven.  However, unlike many of the periods of unseasonably warm weather, there were no highs hotter than 95° in either year.  1964's sultry period was notable because the first three weeks of August had been very cool, five degrees below average, with just one day reporting an above average mean temperature.  

1973 (Aug. 26 - Sept. 5)

Very similar to the late summer heat wave of 1953, this one featured eight days in a row with highs in the 90s, including highs of 98° on 8/28 and again on 8/30.  For the entire eleven-day stretch the average high was 93°.

1979 (Aug. 25 - Sept. 7)

Although three days were in the 90s, what was more striking was the twelve days in a row with lows in the 70s.  The average low during these days was 74°, nine degrees above average. This warm spell was also distinguished by having the smallest difference between the average high and low, twelve degrees.  The only late summer warm spell with a warmer average low would come six years later (but it lasted only five days).  This warm spell featured a cameo by the remnants of hurricane David, which dropped 1.29" of rain on the morning of 9/7.

1980 (Aug. 23 - Sept. 7)

Half of the sixteen days were in the 90s (five of which were 95+) and three other days reached 89°.  The average high for this stretch f days was 90°, ten degrees above average.  (Fifteen days after this hot spell ended the high reached 94° degrees on 9/22.)

1983 (Sept. 3-12)

The highlight was a high of 99° on 9/11, the hottest reading of a hot summer.  And the mercury hit 97° the day before.  Overall, these ten days had an average high of 91°, which was fourteen degrees above average.

2005 (Sept. 12-23)

This was one of the latest of the late incursions of summertime heat; it was also part of 35 days in a row with highs in the 80s that began Aug. 20.  This five-week period was also very dry, with just 0.33" of rain measured in Central Park.

2010 (Aug. 29 - Sept. 2)

The hottest summer on record extended into the first few days of September during this five-day streak of temperatures in the 90s.  And Sept. 3 would probably have reached into the 90s as well if not for cloud cover brought by hurricane Earl (the AM low was a sticky 75°).  Five days after this hot stretch ended saw two days with highs of 89° and 90°.

2014 (Aug. 29 - Sept. 5)

In 2014 New York didn't experience an extended period of hot weather until late in the summer.  Seven of the eight days saw highs of 88° or hotter, with four of them in the low 90s.

2015 (Aug. 30 - Sept 9)

This eleven-day period began with a five-day heat wave and ended with a three-day heat wave, which included the hottest reading of the year, 97°, on Sept. 8. 

2016 (Aug 26-31)

For the third year in a row late summer featured unseasonably warm weather.   Earlier this summer there were two five-day heat waves, and while this six-day period didn't meet the definition of a "heat wave" (i.e., every day has a high of 90+), these days were eight degrees above average.  




2018 (Aug. 27 - Sept. 6)

This eleven-day stretch was comprised of two four-day periods of hot weather at the beginning and end, with three close to average days in between.  Each four-day period had three days in the 90s and three days with lows of 75°+.  The average high/low of the entire eleven days was 88/75°, eight degrees above average.  The average low is the warmest of any late summer hot spell of ten days or longer.


 Chart - Hottest Late Summer

Chart - Last Gasp of Summer


September 2014 Weather Recap: Dry & Warm


September 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 1869. 


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" of rain fell.  Since records began, this ranks as twelfth driest September.  (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.




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).


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).




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).


    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
    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).


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
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, 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














New York Weather History: September (1970 - 2021)




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.


Sept 1

Sept 2

Sept 3

Sept 4

Sept 5

Sept 6

Sept 7

Sept 8

Sept 9

Sept 10

Sept 11

Sept 12

Sept 13

Sept 14

Sept 15

Sept 16

Sept 17

Sept 18

Sept 19

Sept 20

Sept 21

Sept 22

Sept 23

Sept 24

Sept 25

Sept 26

Sept 27

Sept 28

Sept 29

Sept 30




Today in New York Weather History: Labor Day Weekend (1970 - 2021)




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".




  • 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.




  • 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. 




  • 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. 



  • 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).











Warm September Mornings in New York



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



Looking Back at New York Weather: September 30



Today's high was 61°, making this 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).


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).


Today was the 15th day this month with a high cooler than 70°, the most of any September in the years since 1890 (thru 2021).  Before 1890, five years that had this many, or more (Sept. 1871 and 1876 had 17 such days.)


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 5-6 PM dumped a little more than an inch of rain, along with winds that gusted to 40 mph. 


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. 


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  


Today's high of 65° was the 14th cooler than 70° this month, the most in September since 1913 (which had 15).  However, this September had 13 days with highs of 65° or cooler, while Sept. 1913 had only three. 


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.


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


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.


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.


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" was measured).




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.


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.








Today in New York City Weather History: September 29



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).    


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


The morning low was a summer-like 71°, fifteen degrees above average.  This was the latest date 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.


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


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











Today in New York Weather History: September 28


Since 1970, Sept. 28 is the average date of the last reading in the 80s (or warmer) of the year.  It's occurred as early as Sept. 2 (in 1902) and as late as Nov. 15 (in 1993).  This is one month after the average date of the last reading of 90°+ (Aug. 28).



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 8.95" over nine consecutive days.  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°). 


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.  


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


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.





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+

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 degrees above average.


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.



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.)


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.  (An even more impressive monthly rainfall streak would be established on this date in 2021.)


Chart - 3 months 6 inches+ precip


Early afternoon showers amounted to 0.27”, pushing September’s rainfall over ten inches (10.03”).  Not only was this the most rain to fall in September since 2004, it was the third month in a row with more than ten inches of rain  – the first time for such a streak (July had 11.09”, August had 10.32”).  However, this wasn’t Central Park’s rainiest three-month period, as the 31.44” that fell was three inches less than the 34.43” that fell in Aug-Sept-Oct 2011 (18.95”, 9.39” and 6.09”, respectively).