September 2025 OBS-Discussion centered NYC subforum

[SACRUS]

 

39 minutes ago, psv88 said:

 My kids were swimming off the boat on the north shore yesterday. Some of the protected harbors still in the mid 70s by late afternoon on the warmer days 

 

Still upper 60s - low 70s

 

[LibertyBell]

On 9/14/2025 at 7:32 AM, bluewave said:

Even JFK has a shot at 85-90° next Friday as the models have a warm downslope flow now. 

 

It could be the last very warm day of the season, I see my forecast as mid 80s.  We have not been warmer than low 80s since the first half of August, it has nothing to do with the ocean as the flow has been NW most of that time and low humidity, good sky conditions.

 

[LibertyBell]

2 hours ago, bluewave said:

This year has been defined by the sharp cutoffs to the heavy rainfall. The aerial coverage from most events hasn’t been very good. So this allowed MPO to go up 13.00” this year on the precipitation over FWN.
 

Time Series Summary for SUSSEX AIRPORT, NJ
Click column heading to sort ascending, click again to sort descending.

2025-09-15

20.02

17

 

Time Series Summary for Mount Pocono Area, PA (ThreadEx)
Click column heading to sort ascending, click again to sort descending.

1

2025-09-15

33.40

1

wow it's been very wet in the Poconos!

today is my birthday so thanks for the YTD right to my birthday Chris!!

[LibertyBell]

2 hours ago, bluewave said:

Quite a big departure spread this month. The cooler spots have a shot at finishing the month with a small cold departure. But the warmer stations like EWR, HPN, and ISP could finish with a small warm departure. 

ISP….-1.2

HPN….-1.4

EWR…..-1.4

NYC…..-2.3

BDR……-2.5

LGA……-2.9
 

we should finish below normal here.

I don't know how Islip is so warm lol

 

[LibertyBell]

3 hours ago, Sundog said:

This is the wettest Euro run yet for the coastal low. This is 6z:

 

why do we call this a coastal low instead of a noreaster?

any storm with NE winds should be referred to as a noreaster, I noticed the media is calling it a coastal low too.

 

[LibertyBell]

6 hours ago, bluewave said:

The source region to our west has been record dry since August 1st.

 

 

nice low humidity, 1980s type weather is back

 

[LibertyBell]

7 hours ago, SACRUS said:

Records:

Highs:

EWR: 94 (1983)
NYC: 92 (1927)
LGA: 91 (1993) 
JFK: 85 (2008)


Lows:

EWR: 47 (1975)
NYC: 44 (1873)
LGA: 49 (1975)
JFK: 45 (1975)

Historical:

 

 

1747: Some historical accounts of a hurricane caused flooding on the Rappahannock River in Virginia. A slave ship was overturned, and several fatalities were reported.

 

1752 - A great hurricane produced a tide along the South Carolina coast which nearly inundated downtown Charleston. However, just before the tide reached the city, a shift in the wind caused the water level to drop five feet in ten minutes. (David Ludlum)

1910 - Rains of .27 inch on the 14th and .73 inch on the 15th were the earliest and heaviest of record for Fresno CA, which, along with much of California, experiences a ""rainy season"" in the winter. (The Weather Channel)

1916: St. Paul's earliest snow ever. (Ref. AccWeather Weather History)

1922: The noon wet bulb temperature of 79.3°F was the highest ever-recorded in Washington, DC until this date. (Ref. Washington Weather Records - KDCA)

1939 - The temperature at Detroit MI soared to 100 degrees to establish a record for September. (The Weather Channel)

1939" The temperature at Detroit MI soared to 100 °F to establish a record for September. (The Weather Channel)
(Ref. WxDoctor) (Ref. Many Additional Temperatures Listed On This Link)

1944: Boston, Massachusetts recorded its lowest September pressure of 28.62 inches of mercury from the "Great Atlantic Hurricane". (Ref. NOAA Boston Weather Events)

1945: A hurricane entered the south Florida coast at Homestead, curving northward right up through the center of Florida, remaining over land, and exited near Jacksonville Beach with winds gusting to 170 mph. The following is from the Homestead Air Reserve Base. “On Sept. 15, 1945, three years to the day after the founding of the Homestead Army Air Field, a massive hurricane roared ashore, sending winds of up to 145 miles per hour tearing through the Air Field's buildings. Enlisted housing facilities, the nurses' dormitory, and the Base Exchange were all destroyed. The roof was ripped from what would later become building 741, the Big Hangar. The base laundry and fire station were both declared total losses. The few remaining aircraft were tossed about like leaves.”

1965: Heavy snow across parts of Wyoming from the 13th through the 15th was by far the heaviest for so early in the season, resulting in 23 inches in Rawlins and 20.7 inches in Lander. (Ref. AccWeather Weather History)


1975: Marilyn struck the Virgin Islands as a Category 3 Hurricane with maximum sustained winds of 115 mph and an estimated minimum central pressure of 952 millibars or 28.11 inches of mercury. The strongest, most damaging part of the storm passed directly over the island of St. Thomas. The island of Culebra reported an unofficial wind gust of 125 mph. Storm surge was generally 6 to 7 feet with an isolated 11.7 storm surge in St. Croix. 80% of the homes and business on St. Thomas were destroyed and 10,000 people were left homeless. 30% of the homes on St. John were destroyed and 60% were left roofless. Marilyn caused 8 deaths and $1.5 billion dollars in damage. (Ref. Wilson Wx. History)

1977: Sioux Falls, SD residents received a rude awakening during the morning hours as thunderstorms rolled through the city. Over 2.5 inches of rain fell in the city in an hour and 15 minutes. The large amount of rain in a short period of time led to street flooding in some areas. Lightning strikes from the storms also started several fires. (Ref. Wilson Wx. History)
 

1982 - A snowstorm over Wyoming produced 16.9 inches at Lander to esablish a 24 hour record for September for that location. (13th-15th) (The Weather Channel)

1987 - The first snow of the season was observed at the Winter Park ski resort in Colorado early in the day. Eight inches of snow was reported at the Summit of Mount Evans, along with wind gusts to 61 mph. Early morning thunderstorms in Texas produced up to six inches of rain in Real County. Two occupants of a car drowned, and the other six occupants were injured as it was swept into Camp Wood Creek, near the town of Leakey. Late afternoon and evening thunderstorms produced severe weather in central and northeastern Oklahoma. Wind gusts to 70 mph and golf ball size hail were reported around Oklahoma City OK. (National Weather Summary) (Storm Data)

1988 - Thunderstorms brought much needed rains to parts of the central U.S. Rainfall totals of 2.87 inches at Sioux City IA and 4.59 inches at Kansas City MO were records for the date. Up to eight inches of rain deluged the Kansas City area, nearly as much rain as was received the previous eight months. Hurricane Gilbert, meanwhile, slowly churned toward the U.S./Mexican border. (The National Weather Summary)

1989 - Showers and thunderstorms produced locally heavy rain in the Central Appalachians. Virgie VA received 2.60 inches of rain during the evening hours, and Bartlett TN was deluged with 2.75 inches in just ninety minutes. Heavy rain left five cars partially submerged in high water in a parking lot at Bulls Gap TN. Thunderstorms over central North Carolina drenched the Fayetteville area with four to eight inches of rain between 8 PM and midnight. Flash flooding, and a couple of dam breaks, claimed the lives of two persons, and caused ten million dollars damage. Hugo, churning over the waters of the Carribean, strengthened to the category of a very dangerous hurricane, packing winds of 150 mph. (Storm Data) (The National Weather Summary)

1995: Hurricane Marilyn strikes Virgin Islands. It hit the U.S. Virgin Islands as a strong category 2 storm with top winds of 115 mph. The strongest, most damaging part of the storm passed directly over St. Thomas Island. It caused 8 deaths and $1.5 billion in damages. (Ref. AccWeather Weather History)



2004: (Sep. 13th-16th) Hurricane Ivan affected coastal AL/W FL Panhandle; landfall occurred near Gulf Shores, AL, early on 16th. A buoy just S of the AL coastal waters reported an incredible peak wave height of 52 feet today before breaking loose of its mooring.
(Ref. Weather Guide Calendar with Pheno

 

2010: The largest hailstone in Kansas was found in southwest Wichita. It measured 7.75 inches in diameter.

 

2011: An EF0 Waterspout moved ashore in Ocean City, Maryland.

This is very weird, did the same hurricane return 20 years later Tony??

 

1975: Marilyn struck the Virgin Islands as a Category 3 Hurricane with maximum sustained winds of 115 mph and an estimated minimum central pressure of 952 millibars or 28.11 inches of mercury. The strongest, most damaging part of the storm passed directly over the island of St. Thomas. The island of Culebra reported an unofficial wind gust of 125 mph. Storm surge was generally 6 to 7 feet with an isolated 11.7 storm surge in St. Croix. 80% of the homes and business on St. Thomas were destroyed and 10,000 people were left homeless. 30% of the homes on St. John were destroyed and 60% were left roofless. Marilyn caused 8 deaths and $1.5 billion dollars in damage. (Ref. Wilson Wx. History)

1995: Hurricane Marilyn strikes Virgin Islands. It hit the U.S. Virgin Islands as a strong category 2 storm with top winds of 115 mph. The strongest, most damaging part of the storm passed directly over St. Thomas Island. It caused 8 deaths and $1.5 billion in damages. (Ref. AccWeather Weather History)

[anthonymm]

9 minutes ago, LibertyBell said:

It could be the last very warm day of the season, I see my forecast as mid 80s.  We have not been warmer than low 80s since the first half of August, it has nothing to do with the ocean as the flow has been NW most of that time and low humidity, good sky conditions.

 

The last couple days of Sept scares me. GFS has been hinting at a torchfest. 

[SACRUS]

43 minutes ago, LibertyBell said:

This is very weird, did the same hurricane return 20 years later Tony??

 

1975: Marilyn struck the Virgin Islands as a Category 3 Hurricane with maximum sustained winds of 115 mph and an estimated minimum central pressure of 952 millibars or 28.11 inches of mercury. The strongest, most damaging part of the storm passed directly over the island of St. Thomas. The island of Culebra reported an unofficial wind gust of 125 mph. Storm surge was generally 6 to 7 feet with an isolated 11.7 storm surge in St. Croix. 80% of the homes and business on St. Thomas were destroyed and 10,000 people were left homeless. 30% of the homes on St. John were destroyed and 60% were left roofless. Marilyn caused 8 deaths and $1.5 billion dollars in damage. (Ref. Wilson Wx. History)

1995: Hurricane Marilyn strikes Virgin Islands. It hit the U.S. Virgin Islands as a strong category 2 storm with top winds of 115 mph. The strongest, most damaging part of the storm passed directly over St. Thomas Island. It caused 8 deaths and $1.5 billion in damages. (Ref. AccWeather Weather History)

 

1995 is the correct year.   There was an issue copying it over 0 good catch.

[Roger Smith]

Here's a detailed study of cases where second half of September was warmer than first half at NYC (or to complete top 25, a few cases of least cooling).

For all data, the September 1-15 mean is 70.7, the September 16-30 mean is 65.4 and the decrease is 5.3 (F deg)

For 1991-2020, the corresponding values are 71.7 _____ 66.5 _____ and 5.2 F deg. 

The top twenty-five Septembers in terms of anomalous temperature averages from first to second half, favoring second half warmth, are as follows. 

Rank ____ Year ____ 1-15 ___ 16-30 ___ diff ____ rank of 2nd half

_01 _____ 2017 ____ 67.7 ___ 73.3 ____ +5.6 _______2

_02 _____ 1891 ____ 70.1 ____74.1 ____ +4.0 _______ 1

_03 _____ 1946 ____ 68.7 ___70.9____ +2.2 ______ 10

_04 _____ 1895 ____ 71.1 ____72.2 ____ +1.1 _______ 4

_05 _____ 1970 ____ 70.3 ___ 71.3 ____ +0.9 *_____ 7t

_06 _____ 1968 ____70.1 ___ 71.0 ____ +0.9 _______ 9

_07 _____ 1917 ____ 63.2 ___ 63.9 ____ +0.6 *

_08 _____ 1870 ____ 67.9 ___ 68.4 ____ +0.5

_09 _____ 1914 ____ 66.5 ___ 66.8 _____ +0.3

_10 ______1892 ____ 64.0 ___ 64.1 _____ +0.2 *

_11 ______2006 ____66.5 ___ 66.6 ____ +0.1  

_12 _____ 1986 ____ 67.9 ___ 67.8 ____ - 0.1

_13 ______1926 ____ 65.9 ___ 65.5 ____ - 0.4

_14 _____ 1883 ____ 62.0 ___ 61.5 ____ - 0.5

_15 _____ 2019 ____ 70.7 ___ 70.1 ____ - 0.6 _______ 11

_16 _____ 1902 ____ 66.9 ___ 66.0 ____ - 0.9

_17t_____ 1908 ____ 69.4 ___ 68.4 ____ - 1.0

_17t_____ 1911 _____ 68.2 ___ 67.2 ____ - 1.0

_17t_____ 1933 ____ 70.0 ___ 69.0 ____ - 1.0

_20 _____ 1920 ____ 69.0 ___ 67.9 ____ - 1.1

_21t_____ 1881 _____ 73.9 ___ 72.7 ____ - 1.2 _______ 3

_21t_____ 1905 _____ 70.4 ___ 69.2 ____ -1.2 

_21t_____ 2003 _____68.5 ___ 67.3 ____ - 1.2

_24 _____ 1930 _____72.6 ___ 71.3 ____ -1.3 _______ 7t

_25 _____ 1965 _____ 68.1 ___ 66.8 ____ -1.4 *

(2024 was fairly close to making list at -1.6 from 69.6 to 68.0)

____________

* Second decimals in data cause rounding result to be different from one-decimal differences in these cases

=== ===

Note that nine of the top eleven warmest second halves of September appear in this top 25. Exceptions were 2005 (75.2, 71.4 - rank t5th, drop 3.8) 2015 (77.5, 71.4 - rank t5th) dropped 6.2F. Also t12th place 1921 (69.7) dropped 4.8 from 74.5 F while t12th 2010 (also 69.7) dropped 2.8 from 72.5; 14th place (69.4) 1959 dropped 5.8 from 75.2. 15th place 1905 (69.2) is in the list above, 16th place 1906 (69.1) is not in list (dropped 2.4 from 71.5) and tied 17th for warmest second half is 69.0, one is in the list above (1933) and the other is 1998 which dropped 2.5 from 71.5. 19th warmest second half is 68.8 in 1985 and t20th is 68.7 in 2002 and 2021. These three all had moderate falls from warmer first halves. 1884 (68.6) and 1898 (68.5) were next in line and both fell over 4F to reach those still-very warm values. Tied 25th at 68.4 were 1870 and 1908 (in list), 2007 and 2016. 

There is a noticeable tendency for these warm second-half cases (whether in list or not) to be followed by several weeks of very warm weather in October, which is probably not surprising given the persistence of pattern often seen in early to mid autumn. Yet also the most conspicuous counter-example (see top ten counter-examples list below text) 1947 also was followed by a very warm October as were 1897, 1900 and 1961 in that list. 1875 stayed very cold, 1929 was generally cold in October also.

A few years made this list by having a very chilly first half and a near or closer to average second half (1917, 1883 in particular)

There are quite a few solid winters that followed years in this list (1917-18 and 1933-34 in particular, also 2017-18, 1892-93, 1870-71, 1968-69, 1911-12).

Remains to be seen where 2025 will stack up against this top 25. The first half mean is 69.9F. An average of 69.2 by end of month will likely place 2025 in the above list. An average of 49 would be needed to get into the list below so that's not going to happen.

========== 

(top ten counter-examples, falling averages in Sep)

_01 __ 1947 ___ 77.3 _ 59.9 __ -17.4 F

_02 __ 2023 ___76.0 _62.8 __ -13.2 F

_03 __ 1875 ___ 70.4 _ 57.4 __ -13.0 F

_04 __ 1993 ___ 73.5 _ 61.0 __ -12.5 F

_05 __ 1929 ___ 75.5 _ 63.2 __ -12.3 F

_06t__ 1961 ___ 79.1 _ 67.8 __ -11.4 F *

_06t__ 1996 ___ 73.7 _ 62.3 __ -11.4 F

_08t__ 1897 ___ 72.6 _ 61.5 __ -11.1 F 

_08t__ 1915 ___ 75.5 _ 64.4 __ -11.1 F

_10t__ 1900 ___ 76.3 _ 65.5 __ -10.8 F

_10t__ 1983 ___ 77.2 _ 66.3 __ -10.8 F *

_10t__ 1990 ___ 72.9 _ 62.1 __ -10.8 F

_______

* Second decimals in data cause rounding result to be different from one-decimal differences in these cases

Most of the top ten twenty first halves (above 74F) are in the above list; 2015 (77.5) and 2005 (75.1) are discussed in slight-fall cases, and other contenders with average drops are 1884 (74.9) 1898 (76.3) 1931 (76.5) 1944 (74.1) 1945 (74.7) 1971 (75.8) 1979 (74.6) 1980 (75.7) and 2016 (75.2). 

1953 and 1973 with strong heat waves at start of September had first half averages close to 74F. They cooled off fairly quickly. 

The coldest second half of September by the way was 56.4 in 1871. The lowest value since 1980 is 61.0 (1993) followed by 61.3 in 2000.

 

 

[weatherpruf]

2 hours ago, SACRUS said:

 

 

Still upper 60s - low 70s

 

took a ride by boat from sayreville nj friday to the western sound....was fishing by some lighthouse east of new rochelle....wind was snotty in the morning and not what we expected, but it laid down by afternoon. wound up with about 25 keeper porgies, not great but not bad, given the early winds. left the dock in nj at 6 am didn't get back til 9 pm due to the late bite; we left the sound at around 6 pm. had to go slow in the dying light through the east river and harbor. water felt a bit cold to me but it could have been the east wind cooling the surface....