September 2025 OBS-Discussion centered NYC subforum

[psv88]

Looks like we take a step down by the end of next week. Low 60s highs. Usually our first cool day with highs under 60 is first week of October so we are on schedule 

[donsutherland1]

Newark has reached 80 for the fourth consecutive day. The last time that happened after September 20th was October 1-4, 2023.

[the_other_guy]

This has to be one of the most consistently warm Septembers I remember. Not hot…just warm

[donsutherland1]

24 minutes ago, the_other_guy said:

This has to be one of the most consistently warm Septembers I remember. Not hot…just warm

The consistency has been remarkable.

Smallest Mean Temperature Standard Deviation for September (through September 25th for 2025) for Central Park:

1. 1968 3.43°
2. 2025 3.75° (10th smallest difference between the mean temperatures for the first and second halves of September)
3. 1870 3.81° (6th smallest difference between the mean temperatures for the first and second halves of September)
4. 2024 3.94°
5. 1908 4.08°

[Superstorm]

17 minutes ago, donsutherland1 said:

The consistency has been remarkable.

Smallest Mean Temperature Standard Deviation for September (through September 25th for 2025) for Central Park:

1. 1968 3.43°
2. 2025 3.75° (10th smallest difference between the mean temperatures for the first and second halves of September)
3. 1870 3.81° (6th smallest difference between the mean temperatures for the first and second halves of September)
4. 2024 3.94°
5. 1908 4.08°

Wow!  Incredible stat.

[donsutherland1]

Westhampton reached 81° this afternoon. That broke the daily record of 80° from 1961.

[uofmiami]

3 hours ago, psv88 said:

Looks like we take a step down by the end of next week. Low 60s highs. Usually our first cool day with highs under 60 is first week of October so we are on schedule 

I'd add 5 degrees to that step down, we'll be 65-70 for highs.  We are on the western fringe of the cold pool aloft, as the cold shot is now offshore from earlier runs this week.  Then back to the 70s for highs with the warmth continuing again.

[FPizz]

10 minutes ago, uofmiami said:

I'd add 5 degrees to that step down, we'll be 65-70 for highs.  We are on the western fringe of the cold pool aloft, as the cold shot is now offshore from earlier runs this week.  Then back to the 70s for highs with the warmth continuing again.

First step down for me was adjusting the time the landscape lights popped on.  Second step down is the pool closing on Monday haha. After that is shutting off the irrigation system :D

[donsutherland1]

Newark has reached 86°. That's the fourth time it has reached 86° or above during the second half of September. The last time there were at least four such days during the second half of September was 2019 when there were five such days.

[lee59]

55 minutes ago, donsutherland1 said:

Westhampton reached 81° this afternoon. That broke the daily record of 80° from 1961.

That is a low record high, even for Westhampton. Meanwhile my high today was 81.

[donsutherland1]

Rainfall amounts in the New York City area were generally less than the 0.50"-1.50" forecast amounts. There was a stripe of heavier rainfall in parts of Connecticut.

Storm total amounts included:

Hartford: 1.72"
Islip: 0.30"
New Haven: 1.34"
New York City-Central Park: 0.35"
New York City-JFK Airport: 1.38"
New York City-LaGuardia Airport: 0.33"
Newark: 0.17"
Storrs: 2.76"
White Plains: 0.47"

As a result, New York City is on track to finish with rainfall that is below the 4.31" monthly normal value for September. Almost as if to add insult to injury to the dry New York City area, in the past hour, Phoenix has picked up 1.09" of rain, along with winds gusting to 56 mph. The 1.11" so far today is its biggest rainstorm since October 13, 2018.

Above normal temperatures will continue through the remainder of September. Another round of showers is possible Saturday night into Sunday. A significant rainfall is unlikely.

The guidance and historical experience following a second half September mean temperature of 70° or above suggest that October will be warmer than normal in the New York City area. The two most recent Octobers with a cooler than normal first half like 2025 and a second half with a mean temperature of 70° or above were: 2017 (October mean temperature: 64.1° and October 2019: October mean temperature 59.9°).

The extent of ridging to the north and interaction between the Humberto and Invest. 94 could ultimately determine whether Invest. 94 poses an eventual threat to a portion of the Southeast or stays out to sea.

The potential Fujiwhara interaction would be unusual for the Atlantic basin. Typically, if the stronger system is to the right or east of the weaker one (possibly Invest. 94 as per most of the guidance at present), the stronger system will tend to deflect the weaker one northward and eastward sooner than might otherwise be the case. If both systems are of similar strength, they can rotate counterclockwise around a midpoint roughly between the centers of the two storms as they move along the steering flow. Two plausible scenarios are landfall along the South Carolina coast or a sharp turn out to sea after an approach toward the coastline. 

For now, tropics bear watching for the Southeast. 

The ENSO Region 1+2 anomaly was 0.0°C and the Region 3.4 anomaly was -0.4°C for the week centered around September 17. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.03°C and the ENSO Region 3.4 anomaly has averaged -0.38°C. La Niña conditions will likely develop during mid- or late-autumn.

The SOI was +9.81 today. 

The preliminary Arctic Oscillation (AO) was +1.341 today. 

Based on sensitivity analysis applied to the latest guidance, there is an implied near 86% probability that New York City will have a warmer than normal September (1991-2020 normal). September will likely finish with a mean temperature near 70.1° (0.9° above normal). 

Supplemental Information: The projected mean would be 2.1° above the 1981-2010 normal monthly value.

 

[donsutherland1]

1 hour ago, lee59 said:

That is a low record high, even for Westhampton. Meanwhile my high today was 81.

It was. Islip also tied its daily record of 85° from 1970.

[WestBabylonWeather]

Sitting on the deck right now like it’s July 

[steve392]

75 and sunny in Mahwah.  Gorgeous out.

[winterwarlock]

84/71/86

4th day in row  80 plus with several more to come

Summer

 

 

[qg_omega]

very dry stretch upcoming after tomorrow night, could last weeks again

[winterwarlock]

5 hours ago, psv88 said:

Looks like we take a step down by the end of next week. Low 60s highs. Usually our first cool day with highs under 60 is first week of October so we are on schedule 

Usually we have a high in the 60s with full sun by mid September so this year its way late and its only day so very weak with any cool down this year

[lee59]

22 minutes ago, donsutherland1 said:

It was. Islip also tied its daily record of 85° from 1970.

I was surprised Islip got that warm, only made it to 81 here.

[Stormlover74]

2 hours ago, qg_omega said:

very dry stretch upcoming after tomorrow night, could last weeks again

Yep

[SACRUS]

 

Highs:

 

TEB: 87
EWR: 86
ISP: 85
ACY: 85
BLM: 84
LGA: 84
PHL: 84
New Brnswck: 83
JFK: 82
TTN: 82
NYC: 82

[Sundog]

Don't despair, the 18z EURO AI loops the tropical system off the coast back into our area day 9. 

[anthonymm]

6 hours ago, uofmiami said:

I'd add 5 degrees to that step down, we'll be 65-70 for highs.  We are on the western fringe of the cold pool aloft, as the cold shot is now offshore from earlier runs this week.  Then back to the 70s for highs with the warmth continuing again.

What is causing the ridiculously consistent +8 F temps above normal literally every single day? Is it just the EPO? It's a january 2023 torch-like pattern.

[anthonymm]

3 hours ago, winterwarlock said:

Usually we have a high in the 60s with full sun by mid September so this year its way late and its only day so very weak with any cool down this year

Wasted the cold air in august and first half of September. I guess it made what is usually the worst part of summer more tolerable but now we have typical late august temps happening in late september-early oct. Fall's taking a break for the foreseeable future.

[Cfa]

Made it up to 87 here, I wish this happened tomorrow (Saturday) instead.

This year has really been a snoozefest on all fronts, the only exception being the 100+ degree heat in June and July.

[FPizz]

11 hours ago, psv88 said:

Looks like we take a step down by the end of next week. Low 60s highs. Usually our first cool day with highs under 60 is first week of October so we are on schedule 

 

[SnoSki14]

5 hours ago, anthonymm said:

What is causing the ridiculously consistent +8 F temps above normal literally every single day? Is it just the EPO? It's a january 2023 torch-like pattern.

It's called climate change and it's only gonna get worse. Endless summer year-round 

[LibertyBell]

18 hours ago, SACRUS said:

 

Records:

 

Highs:

EWR: 90 (2007)
NYC: 91 (1970)
LGA: 90 (2007)
JFK: 87 (1970)



Lows:  

EWR: 40 (1940)
NYC: 42 (1940)
LGA: 44 (1947)
JFK: 47 (1949)

Historical:

 

1936 - Denver, CO, was buried under 21.3 inches of snow, 19.4 inches of which fell in 24 hours. The heavy wet snow snapped trees and wires causing seven million dollars damage. (26th-27th) (David Ludlum) (The Weather Channel)

 

1936: The heaviest snowfall ever recorded in September and the heaviest snowfall ever recorded so early in the season dumped a total of 16.5 inches of snow on downtown Denver and 21.3 inches at Denver Municipal Airport. The 15.0 inches of snow measured from 6:00 PM on the 27th to 6:00 PM on the 28th is the greatest 24-hour snowfall ever recorded in September. This was the first snow of the season. The snow was intermittent on the 26th, but continuous from early afternoon on the 27th to around midnight on the 28th, except for a period of rain during the afternoon of the 28th.

1936:  A forest fire burned several miles east of the town of Brandon, Oregon. The fire was far enough away that residents were not particularly worried. A sudden shift in the winds drove the flames westward and through town. The fire, caused by summer drought and fueled by the abundant Gorse Weed found in many of the empty spaces between buildings in Bandon, caused so much destruction that only a handful of structures were left standing when the fire finally died down. 

1936 - A forest fire burned several miles east of the town of Bandon, Oregon. The fire was far enough away that residents were not particularly worried. A sudden shift in the winds drove the flames westward and through town. The fire, caused by summer drought and fueled by the abundant Gorse Weed found in many of the empty spaces between buildings in Bandon, caused so much destruction that only a handful of structures were left standing when the fire finally died down.

1942: A severe freeze was experienced across the upper Plains and Midwest from the 26th to the 28th. The temperature at Parshall, ND dropped to a record low of 4° on this date. Winona, MN dropped to 25°, their coldest September temperature. Also on this date, snow fell across parts of Minnesota, Iowa and Wisconsin. Locations recording their earliest measurable snowfall included: Caledonia, MN: 5 inches, Fayette, IA: 1 inch and La Crosse, WI: 0.2 of an inch. Snow fell in early morning, mostly melting as it fell. (Ref. AccWeather Weather History)
 

1950 - Residents of the northeastern U.S. observed a blue sun and a blue moon, caused by forest fires in British Columbia. (David Ludlum)

1953: The center of Hurricane Florence hit the northwest Florida coast between Valparaiso and Panama City near midday with wind maximum sustained winds near 80 mph with gusts to 90 mph and heavy rainfall. The Pensacola Weather Bureau Office reported winds of up to 75 mph early the next morning. The storm passed inland over a sparsely settled area of Florida and this probably accounts for the rather small amount of damage. In Franklin and Okaloosa Counties the Red Cross estimated that 273 homes were destroyed, 145 other buildings damaged, and three destroyed. A fishing trawler, the "Miss Tampa" was reported missing in the storm's wake. (Ref. Wilson Wx. History)

 

1955: On this date, the Atlantic reconnaissance aircraft, ”Snowcloud Five” went down while investigating Hurricane Janet and was never heard from again. Lt. Comdr. Windham with a crew of 8 and two newspapermen reported that they were about to begin penetrating the central core of the hurricane.  The hurricane made landfall at peak intensity near Chetumal, Mexico on September 29th. Janet's landfall as a Category 5 hurricane on the Yucatán Peninsula was the first recorded instance that a storm of such intensity in the Atlantic made landfall on a continental mainland; prior to Janet, landfalls of Category 5 intensity were only known to have taken place on islands.

1963 - San Diego, CA, reached an all-time record high of 111 degrees. Los Angeles hit 1S09 degrees. (David Ludlum)

1970 - Santa Ana winds brought fires to Los Angeles County, and to points south and east. Half a million acres were consumed by the fires, as were 1000 structures. Twenty firemen were injured. (25th-29th) (The Weather Channel)

1971: Project Stormfury was an attempt to weaken tropical cyclones by flying aircraft into them and seeding with silver iodide. The project was run by the United States Government from 1962 to 1983. Hurricane Ginger in 1971 was the last hurricane Project Stormfury seeded.

1979 - In the midst of a hot September for Death Valley, California, the afternoon high was 104 degrees for the second of three days, the coolest afternoon highs for the month. (The Weather Channel)

1985: Hurricane Gloria weakened briefly while moving from northeast of the Bahamas to just off the southern North Carolina coast by days end. Gloria peaked the previous day with maximum sustained winds of 145 mph and a minimum central pressure of 920 millibars or 27.17 inches of mercury. Gloria weakened during this date to 90 mph at 06z and 12z before regaining strength intensifying to 100 mph by days end. Washington, DC area was lucky as hurricane Gloria stays well east of Washington, DC. (Ref. Wilson Wx. History)

1987 - Freezing temperatures were reported in the Northern and Central Appalachians, and the Upper Ohio Valley. The morning low of 27 degrees at Concord NH tied their record for the date. Temperatures soared into the 90s in South Dakota. Pierre SD reported an afternoon high of 98 degrees. (The National Weather Summary)

1988 - Unseasonably warm weather prevailed across Florida. Afternoon highs of 92 degrees at Apalachicola and 95 degrees at Fort Myers were records for the date. (The National Weather Summary)

1989 - Rain spread from the southeastern states across New England overnight. Cape Hatteras NC reported measurable rainfall for the fourteenth straight day, with 15.51 inches of rain recorded during that two week period. Phoenix AZ reported a record high of 108 degrees, and a record 134 days of 100 degree weather for the year. Afternoon temperatures were only in the 40s over parts of northwest Wisconsin and Upper Michigan. (The National Weather Summary)

1998: Record warm weather across the Great Lakes and Ohio Valley fueled a severe weather outbreak as a cold front arrived during the late afternoon. A severe thunderstorm produced softball-sized hail in Clare County which smashed skylights, dented automobiles, and damaged roofs and antennas. Damage was estimated at up to half a million dollars. Record highs for the date included: Toledo, OH: 92°, Columbus, OH: 92°, Detroit, MI: 91°, Cleveland, OH: 91°, South Bend, IN: 91°-Tied, Flint, MI: 90°, Chicago, IL: 90°, Grand Rapids, MI: 89°, Lansing, MI: 89°, Jackson, KY: 87° and Mansfield, OH: 87°-Tied. (Ref. Wilson Wx. History)


1998: There were four hurricanes were spinning simultaneously in the Atlantic basin: Georges, Ivan, Jeanne, and Karl. That was the first time this had happened since 1893. 

2004 - After making its infamous loop east of the Bahamas, Hurricane Jeanne made landfall the night of September 26th, 2004. Jeanne came ashore as a major category 3 hurricane just a few miles away from where Hurricane Frances made landfall a few weeks before. Jeanne produced extensive damage along the east central Florida coast from Volusia County south to Martin County. The highest wind gusts occurred over extreme Southern Brevard County as well as Indian River County with 110 - 120 mph estimates at the peak of the storm. (NWS, Melbourne, FL)

1950 - Residents of the northeastern U.S. observed a blue sun and a blue moon, caused by forest fires in British Columbia. (David Ludlum)

a blue sun? I would love to have seen that!

 

about hurricane Gloria in 1985 didn't that storm peak at Cat 5?

1985: Hurricane Gloria weakened briefly while moving from northeast of the Bahamas to just off the southern North Carolina coast by days end. Gloria peaked the previous day with maximum sustained winds of 145 mph and a minimum central pressure of 920 millibars or 27.17 inches of mercury. Gloria weakened during this date to 90 mph at 06z and 12z before regaining strength intensifying to 100 mph by days end. Washington, DC area was lucky as hurricane Gloria stays well east of Washington, DC. (Ref. Wilson Wx. History)

[LibertyBell]

4 hours ago, FPizz said:

 

Yes why are people talking about an October torch when it's supposed to turn chilly as soon as October starts?

 

[LibertyBell]

6 hours ago, Cfa said:

Made it up to 87 here, I wish this happened tomorrow (Saturday) instead.

This year has really been a snoozefest on all fronts, the only exception being the 100+ degree heat in June and July.

it was one of our warmest days of the month, made it to 85 here for the second time since September 20th lol

[LibertyBell]

7 hours ago, SACRUS said:

 

Highs:

 

TEB: 87
EWR: 86
ISP: 85
ACY: 85
BLM: 84
LGA: 84
PHL: 84
New Brnswck: 83
JFK: 82
TTN: 82
NYC: 82

85 here for the second time since September 20 Tony!!