June 2025 discussion-obs: Summerlike

[FPizz]

3 hours ago, Stormlover74 said:

Supposed to rebound later. We shall see

80 again!  Sun trying to pop out

[TheClimateChanger]

1 hour ago, bluewave said:

1949 had record August cold despite the 100° days. So in those days, the heat tended to get balanced out with cold. Plus the following 1950 summer was the 6th coldest on record.
 

Newark Area, NJ
Period of record: 1931-01-01 through 2025-06-25DateLowest minimum temperatures (degrees F)

8/20	52 in 1949	55 in 1943	56 in 2008+
8/21	53 in 1949	53 in 1940	56 in 1977+

Newark Area, NJ
Period of record: 1931-01-01 through 2025-06-25DateHighest maximum temperatures (degrees F)Top Record 2nd Record 3rd Record

8/10	102 in 1949	99 in 2001	97 in 1973+
8/11	102 in 1949	102 in 1944	98 in 2005

 

Time Series Summary for NEWARK LIBERTY INTL AP, NJ
Click column heading to sort ascending, click again to sort descending.

1	1940	71.0	0
2	1946	71.7	0
3	1945	72.4	0
4	1941	72.5	0
5	1936	72.7	0
6	1950	72.8	0
-	1935	72.8	0
-	1933	72.8	0
-	1932	72.8	0

Another interesting thing, seeing 1936 on that list. That really jives with my research. They claim 1936 is the hottest summer on record, tied with 2021. But it looks like it was overall quite cool for most of the eastern United States. Except for that record heat wave that lasted about a week in July, I'd even say downright chilly. Overnight low temperatures were impressively cold in much of rural Pennsylvania that summer. Without that brief stretch, it looks like it would have been one of the coldest on record in many places. Quite odd that it is tied with 2021 for hottest on record.

If you look into the numbers, the heat was driven by ridiculously high 12F anomalies (on the plus side) in states like North Dakota and South Dakota where nobody lived in 1936 (and still few reside to this day). I wonder how much the loss of crops and at least temporary desertification played a role in amplifying those numbers. They adjust for "urbanization" but don't make any adjustment for the massive amounts of irrigation and the unnatural density of corn and soybeans across the Plains and Midwest. Without the UHI adjustments, I bet 2021 would take the crown, and some other recent summers would surpass 1936 as well. Also, not saying they should make any crop-based adjustments, but it does strike me as odd how certain human-caused environmental changes are factored in, but others are not.

[Roger Smith]

2025 reduced 1888 in the roster of all-time records, from 2.0 to 0.5 daily max, and from 1.5 to 0.5 high daily min (it still has a tie with 2015 for a December high min, and it retains a tie with 2025 for June 23rd max. 

2025 also reduced 1909 from 4.0 to 2.0 daily records for high minimum values, and reduced 1952 to a one-third share of monthly high min. 

The counts for June 2025 are 1.5 and 3.0 daily records (max, min) and two-thirds share of the monthly record high min. 

[TheClimateChanger]

5 minutes ago, TheClimateChanger said:

Another interesting thing, seeing 1936 on that list. That really jives with my research. They claim 1936 is the hottest summer on record, tied with 2021. But it looks like it was overall quite cool for most of the eastern United States. Except for that record heat wave that lasted about a week in July, I'd even say downright chilly. Overnight low temperatures were impressively cold in much of rural Pennsylvania that summer. Without that brief stretch, it looks like it would have been one of the coldest on record in many places. Quite odd that it is tied with 2021 for hottest on record.

If you look into the numbers, the heat was driven by ridiculously high 12F anomalies (on the plus side) in states like North Dakota and South Dakota where nobody lived in 1936 (and still few reside to this day). I wonder how much the loss of crops and at least temporary desertification played a role in amplifying those numbers. They adjust for "urbanization" but don't make any adjustment for the massive amounts of irrigation and the unnatural density of corn and soybeans across the Plains and Midwest. Without the UHI adjustments, I bet 2021 would take the crown, and some other recent summers would surpass 1936 as well. Also, not saying they should make any crop-based adjustments, but it does strike me as odd how certain human-caused environmental changes are factored in, but others are not.

I think 1936 sort of gets a pass because people see all the all-time records (including state records) that extend all the way to the East Coast, but it really wasn't that hot of a summer for most areas in the overall means.

[FPizz]

Decent looking line of storms heading in from Poconos area.  

[winterwx21]

8 minutes ago, FPizz said:

80 again!  Sun trying to pop out

Enough sun here now that I popped back up to 79. NWS was right about it rebounding this afternoon. 

[LibertyBell]

1 hour ago, bluewave said:

1949 had record August cold despite the 100° days. So in those days, the heat tended to get balanced out with cold. Plus the following 1950 summer was the 6th coldest on record.
 

Newark Area, NJ
Period of record: 1931-01-01 through 2025-06-25DateLowest minimum temperatures (degrees F)

8/20	52 in 1949	55 in 1943	56 in 2008+
8/21	53 in 1949	53 in 1940	56 in 1977+

Newark Area, NJ
Period of record: 1931-01-01 through 2025-06-25DateHighest maximum temperatures (degrees F)Top Record 2nd Record 3rd Record

8/10	102 in 1949	99 in 2001	97 in 1973+
8/11	102 in 1949	102 in 1944	98 in 2005

 

Time Series Summary for NEWARK LIBERTY INTL AP, NJ
Click column heading to sort ascending, click again to sort descending.

1	1940	71.0	0
2	1946	71.7	0
3	1945	72.4	0
4	1941	72.5	0
5	1936	72.7	0
6	1950	72.8	0
-	1935	72.8	0
-	1933	72.8	0
-	1932	72.8	0

it's fascinating how extreme heat was balanced out with extreme cold.

the same must have happened after 1953 and 1955.

 

[LibertyBell]

16 minutes ago, TheClimateChanger said:

Another interesting thing, seeing 1936 on that list. That really jives with my research. They claim 1936 is the hottest summer on record, tied with 2021. But it looks like it was overall quite cool for most of the eastern United States. Except for that record heat wave that lasted about a week in July, I'd even say downright chilly. Overnight low temperatures were impressively cold in much of rural Pennsylvania that summer. Without that brief stretch, it looks like it would have been one of the coldest on record in many places. Quite odd that it is tied with 2021 for hottest on record.

If you look into the numbers, the heat was driven by ridiculously high 12F anomalies (on the plus side) in states like North Dakota and South Dakota where nobody lived in 1936 (and still few reside to this day). I wonder how much the loss of crops and at least temporary desertification played a role in amplifying those numbers. They adjust for "urbanization" but don't make any adjustment for the massive amounts of irrigation and the unnatural density of corn and soybeans across the Plains and Midwest. Without the UHI adjustments, I bet 2021 would take the crown, and some other recent summers would surpass 1936 as well. Also, not saying they should make any crop-based adjustments, but it does strike me as odd how certain human-caused environmental changes are factored in, but others are not.

1944 was much hotter than 1936. Likewise 1966 was the peak of the heat prior to 1993.

There is a theory out there that the 5 summers between 1944 and 1955 that had extreme heatwaves were hot because of nuclear testing.

1944, 1948, 1949, 1953, 1955

 

 

[FPizz]

4 minutes ago, winterwx21 said:

Enough sun here now that I popped back up to 79. NWS was right about it rebounding this afternoon. 

Never a doubt!  jk  

[LibertyBell]

18 minutes ago, TheClimateChanger said:

Another interesting thing, seeing 1936 on that list. That really jives with my research. They claim 1936 is the hottest summer on record, tied with 2021. But it looks like it was overall quite cool for most of the eastern United States. Except for that record heat wave that lasted about a week in July, I'd even say downright chilly. Overnight low temperatures were impressively cold in much of rural Pennsylvania that summer. Without that brief stretch, it looks like it would have been one of the coldest on record in many places. Quite odd that it is tied with 2021 for hottest on record.

If you look into the numbers, the heat was driven by ridiculously high 12F anomalies (on the plus side) in states like North Dakota and South Dakota where nobody lived in 1936 (and still few reside to this day). I wonder how much the loss of crops and at least temporary desertification played a role in amplifying those numbers. They adjust for "urbanization" but don't make any adjustment for the massive amounts of irrigation and the unnatural density of corn and soybeans across the Plains and Midwest. Without the UHI adjustments, I bet 2021 would take the crown, and some other recent summers would surpass 1936 as well. Also, not saying they should make any crop-based adjustments, but it does strike me as odd how certain human-caused environmental changes are factored in, but others are not.

I hate those corn and soybean crops, all those subsidies have an extremely negative effect upon the environment and on our health.

[SACRUS]

19 minutes ago, FPizz said:

80 again!  Sun trying to pop out

 

breaking out into some sun here in CNJ as well

 

[LibertyBell]

31 minutes ago, TheClimateChanger said:

Very interesting. If you look at the U.S. national temperature records, 1950 was the coldest year overall since 1929, culminating in all-time record cold and snowfall in late November. But 1951 was even colder, reaching temperatures that have been surpassed on the cool side only twice since (1978 & 1979). The winter of 1950-1951 remains the snowiest on record at Pittsburgh. I wonder if the massive Chinchaga firestorm in British Columbia played a role in that impressive national cool spell. You should look at "Black Sunday" in September. Temperatures in the 40s and pitch blackness. We really hadn't seen anything like that again until 2023. Fortunately, it's looking like the Canadian smoke situation has tampered down for the time being, so, hopefully, that won't have a big impact on temperatures the rest of this summer.

November 1950 triple phaser

1953 was our most extreme summer on record never saw anything like it so it rubber banded back to extreme heat again in 1953 and 1955. Then back to cold again for the last few years of the 50s and the early 60s before the historic heat of 1966 and then cold again after that.

 

[Brian5671]

crazy training cells in S NJ and DE right along the front

[LibertyBell]

1 hour ago, TheClimateChanger said:

Looks like a mostly pleasant summer outside of a 5-day heatwave in late August, which, to be honest, was probably urban heat island related anyways. Isn't that the usual explanation for heat extremes these days? Certainly, seems suspect that the Central Park readings went from among the highest in the CWA to among the lowest in the recent heat wave.

In 1948, the first 24 days of August, prior to the heat wave, were pleasantly cool. The mean temperature for that stretch being 72.5F, which has been surpassed on the cool side only three times since (1962, 1992, and 2000).  The average high temperature, a chilly 79.2F. High temperatures that have only been seen once for that period since (2000). A true summer of yesteryear.

No urban heat island in 1948..... that was one of the most historic periods of heat on record with NYC peaking at 103 and three straight days of 100+ and JFK had back to back days of 100+ which has only happened a couple of times and that was the only time it happened after August 20.

1953 was much more extreme though and it has records for longest heatwave and peak September heat that still stand to this day.

 

[TheClimateChanger]

5 minutes ago, LibertyBell said:

November 1950 triple phaser

1953 was our most extreme summer on record never saw anything like it so it rubber banded back to extreme heat again in 1953 and 1955. Then back to cold again for the last few years of the 50s and the early 60s before the historic heat of 1966 and then cold again after that.

 

1954 had at least a brief shot of extreme heat as well, but maybe it didn't reach all the way to the coast. I know Ohio and western Pennsylvania had 99-100+ temperatures widespread on the 14th. Typically, the coastal Plain is several degrees (3-6F) warmer during hot spells, but maybe the air mass petered out. I believe those heat waves were enhanced by drought in the middle of the country as well, similar but not as extreme as the 1930s drought.

[FPizz]

1 minute ago, Brian5671 said:

crazy training cells in S NJ and DE right along the front

Yeah, hard for anyone to notice with the 3 guys bouncing posts off each other like its their job that has zero to do with obs. 

[LibertyBell]

Just now, TheClimateChanger said:

1954 had at least a brief shot of extreme heat as well, but maybe it didn't reach all the way to the coast. I know Ohio and western Pennsylvania had 99-100+ temperatures widespread on the 14th. Typically, the coastal Plain is several degrees (3-6F) warmer during hot spells.

It did I think 1954 hit 100+ in NYC twice.  Back then with the drier climate it was much easier to reach 100+  It was also easier to be colder.  On the coast, extremes have a lot to do with how much moisture is in the air.

[LibertyBell]

1 hour ago, TheClimateChanger said:

Looks like a mostly pleasant summer outside of a 5-day heatwave in late August, which, to be honest, was probably urban heat island related anyways. Isn't that the usual explanation for heat extremes these days? Certainly, seems suspect that the Central Park readings went from among the highest in the CWA to among the lowest in the recent heat wave.

In 1948, the first 24 days of August, prior to the heat wave, were pleasantly cool. The mean temperature for that stretch being 72.5F, which has been surpassed on the cool side only three times since (1962, 1992, and 2000).  The average high temperature, a chilly 79.2F. High temperatures that have only been seen once for that period since (2000). A true summer of yesteryear.

Can't downplay the extreme devastation caused by this heatwave.

AI Overview

 

The summer of 1948 included a notable heat wave, particularly in late August. While not as severe as the 1936 heat wave, it caused significant heat-related deaths and disruptions, especially in urban areas. In New York City, the heat wave resulted in over 1,000 excess deaths, according to the Boston Review. 

 

Here's a more detailed look:

• Timing and Severity:

  The August 1948 heat wave was particularly intense, exceeding the severity of a heat wave eleven years earlier. 

   
• Impact in New York City:

  The heat wave caused over 1,000 excess deaths in the city. 

   
• Disruptions:

  The heat wave led to widespread power outages, strained infrastructure, and impacted daily life for many, according to The New York Times. 

   
• Historical Context:

  While the 1936 heat wave remains the most severe in terms of widespread impact and duration, the 1948 heat wave serves as a reminder of the vulnerability of urban populations to extreme heat and the need for preparedness. 

   
• Specific Examples:

  In one instance, a delegation had to arrange for city water after a school providing water access closed, and the Bronx Zoo reported significantly lower attendance than on a typical summer Sunday. 

   
• Drownings and Heat Prostration:

  The heat wave was also marked by drownings and deaths due to heat prostration. 

[LibertyBell]

6 minutes ago, TheClimateChanger said:

1954 had at least a brief shot of extreme heat as well, but maybe it didn't reach all the way to the coast. I know Ohio and western Pennsylvania had 99-100+ temperatures widespread on the 14th. Typically, the coastal Plain is several degrees (3-6F) warmer during hot spells, but maybe the air mass petered out. I believe those heat waves were enhanced by drought in the middle of the country as well, similar but not as extreme as the 1930s drought.

this is an interesting article, it puts extreme heatwaves into a historical perspective, they talk about the lengthy 1980 and 1983 heatwaves which were 2 month heatwaves for a large part of the country, as well as the 1948 and 1966 historic heatwaves

 

https://www.bostonreview.net/articles/heat-death/

[LibertyBell]

2 minutes ago, LibertyBell said:

this is an interesting article, it puts extreme heatwaves into a historical perspective, they talk about the lengthy 1980 and 1983 heatwaves which were 2 month heatwaves for a large part of the country, as well as the 1948 and 1966 historic heatwaves

 

https://www.bostonreview.net/articles/heat-death/

https://www.nytimes.com/2025/06/24/nyregion/nyc-heat-wave.html

This article from 2 days ago also mentions the August 1948 heatwave and compares it to what just happened but it's paywalled =\

[LibertyBell]

9 minutes ago, TheClimateChanger said:

1954 had at least a brief shot of extreme heat as well, but maybe it didn't reach all the way to the coast. I know Ohio and western Pennsylvania had 99-100+ temperatures widespread on the 14th. Typically, the coastal Plain is several degrees (3-6F) warmer during hot spells, but maybe the air mass petered out. I believe those heat waves were enhanced by drought in the middle of the country as well, similar but not as extreme as the 1930s drought.

yes most of those earlier years heatwaves were drought driven, with less moisture in the air back then, the temperatures were cooler at night but when a hot airmass was around it was easier to get to triple digits.  Summer 1966 being a case in point, the driest year on record in NYC and the only one in which 100 degrees was reached during three different heatwaves and a total of four times.  1953 was another very dry year and the only other one in which NYC had 4 100+ degree days.

Have a look at this chart

 

https://www.weather.gov/okx/100degreedays

 

[Stormlover74]

76 and mostly sunny

[Roger Smith]

There was a considerable urban heat island in 1948, actually, you could rate it as 60 to 70 per cent of the present urban heat island. Perhaps most of its influence would be on overnight lows. But even by around 1890 to 1900 large cities were beginning to display an urban heat island. Vehicle traffic is only a small component of the cause of a heat island, the main components are altered surface albedos and escape of building heat. People were heating their houses before they had cars. Also they had transformed the urban environments to allow horse and carriage movement (thus changing heat retention). The strength of an urban heat island falls off rapidly after the first 100,000 of population in an urban area is reached and begins for towns as small as 2,000 population based on extensive research by many climatologists. You'd perhaps be surprised how quickly an urban heat island develops and how slowly it increases once developed, if you hadn't done active research or read the literature.

For my Toronto data I estimated the urban heat island began in the 1881-1890 decade (rated at 0.1 C differential then) and I took an arbitrary 0.1 increase each decade to 1971-1980 (adding 1.0 then). For 1981-1990 and the past 35 years I estimated it had stabilized at 1.1 C (2.0 F) deg. For NYC data I have assumed the same pace of change except that I would expect an increase had already begun for 1869 to 1880 so if I had data as far back as Toronto's 1840 startup, I would start modifying 1861-1870 at 0.2 F or 0.1 C and adding that amount every decade so the stable period of 1981-2025 would be actually +1.3 C (+2.34 F) relative to what NYC might record in an unaltered "rural" state. 

Now some might instantly say, but NYC is in a megalopolis much larger than greater Toronto, would it not warm up even more? Perhaps, but as I said, past 100,000 the rate of increase is very slow and probably past 5 million it cannot increase because the environment is so substantially altered on a regional basis. The strength of the greater New York heat island is probably well over +1.5 F out into parts of west central NJ near the end of suburban sprawl. 

As to the urban park question and temperature reductions in hot weather, that probably washes out of data sets fairly quickly as there aren't all that many hot days and the nights in question remain more affected anyway. Urban heat islands tend to be something like 75% minimum boosts and 25% maximum boosts, an estimate of a +2.0 heat island really means +1.0 for average maximum and +3.0 for average minimum. Large stretches of cloudy wet weather show very small urban heat island effects, dry and clear months would have larger differentials. 

[bluewave]

The NAM is finally getting replaced after they stop updating it in March 2017.

 

Public Information Statement 25-41

National Weather Service Headquarters Silver Spring, MD

845 AM EDT Thu Jun 26 2025

To: Subscribers:

-NOAA Weather Wire Service

-Emergency Managers Weather Information Network

-NOAAPORT

Other NWS Partners, Users and Employees

From: Richard Bandy

Acting Director

NCEP/Environmental Modeling Center

Subject: Soliciting Comments on Proposed Discontinuation of the North

American Mesoscale (NAM) model and other Regional Modeling Systems to be

Replaced by the Rapid Refresh Forecast System (RRFS) through July 26,

2025.

The Environmental Modeling Center (EMC) at the National Centers for

Environmental Prediction (NCEP) is working towards replacing the North

American Mesoscale (NAM) model, the High Resolution Window (HiresW) aside

from the Guam domain, the High Resolution Ensemble Forecast (HREF) and

the North American Rapid Refresh Ensemble (NARRE) systems with the

implementation of the Rapid Refresh Forecast System (RRFS) in early 2026.

The NWS is seeking comments on this proposed change through July 26,

2025.

This transition to RRFS would provide an hourly updating modeling system

over a North America region at 3 km horizontal grid spacing, which,

combined with the model retirements, would greatly unify and simplify the

“convective scale” (approximately 3 km grid spacing) regional models

within the NWS operational modeling suite.

As a deterministic system running to 84 h, the RRFS would fully retire

the NAM, and nearly fully retire the HiresW (aside from the Guam domain).

As an ensemble forecast system, the RRFS Ensemble Forecast System (REFS)

would fully retire the HREF and NARRE systems.

The deterministic RRFS generates full domain output at 3 km grid spacing,

and subset grid output over the contiguous United States (CONUS) and

Alaska (AK) (at 3 km grid spacing), and Hawaii (HI) and Puerto Rico (PR)

(at 2.5 km grid spacing). The RRFS will also provide output from a

separate 1.5 km RRFS fire weather run, with output provided over a 5 x 5

degree rotated latitude longitude region. Details of the RRFS output

grids are available in

https://www.emc.ncep.noaa.gov/mmb/mpyle/rrfs_info/rrfs_grids.txt

Relative differences between RRFS output products and the proposed-to-be-

retired system products will be discussed individually by the modeling

[donsutherland1]

Tomorrow will be unseasonably cool. The mercury could struggle to reach 70° in New York City. It should rise into the lower 70s at Newark.

The chilly highs will challenge the record for lowest high temperatures two days after an 80° or above low at Central Park, JFK Airport, and Newark. The existing records are below:

Central Park: 71°, July 9, 1883
JFK Airport: 76°, July 23, 2019
Newark: 76°, July 23, 2019 

All of those readings followed lows of 80° two days earlier.

Central Park has had 72 lows of 80° or above; Newark has had 50; and, JFK Airport has had 16.

Temperatures will return mainly to the lower 80s for the remainder of June. Excessive heat does not appear likely to return in the near-term.

The ENSO Region 1+2 anomaly was +1.0°C and the Region 3.4 anomaly was 0.2°C for the week centered around June 18. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.47°C and the ENSO Region 3.4 anomaly has averaged -0.03°C. Neutral ENSO conditions will likely continue through at least late summer.

The SOI was +12.65 yesterday. 

The preliminary Arctic Oscillation (AO) was +1.073 today. 

Based on sensitivity analysis applied to the latest guidance, there is an implied 93% probability that New York City will have a warmer than normal June (1991-2020 normal). June will likely finish with a mean temperature near 73.1° (1.1° above normal). 

 

[Sundog]

43 minutes ago, Roger Smith said:

There was a considerable urban heat island in 1948, actually, you could rate it as 60 to 70 per cent of the present urban heat island. Perhaps most of its influence would be on overnight lows. But even by around 1890 to 1900 large cities were beginning to display an urban heat island. Vehicle traffic is only a small component of the cause of a heat island, the main components are altered surface albedos and escape of building heat. People were heating their houses before they had cars. Also they had transformed the urban environments to allow horse and carriage movement (thus changing heat retention). The strength of an urban heat island falls off rapidly after the first 100,000 of population in an urban area is reached and begins for towns as small as 2,000 population based on extensive research by many climatologists. You'd perhaps be surprised how quickly an urban heat island develops and how slowly it increases once developed, if you hadn't done active research or read the literature.

For my Toronto data I estimated the urban heat island began in the 1881-1890 decade (rated at 0.1 C differential then) and I took an arbitrary 0.1 increase each decade to 1971-1980 (adding 1.0 then). For 1981-1990 and the past 35 years I estimated it had stabilized at 1.1 C (2.0 F) deg. For NYC data I have assumed the same pace of change except that I would expect an increase had already begun for 1869 to 1880 so if I had data as far back as Toronto's 1840 startup, I would start modifying 1861-1870 at 0.2 F or 0.1 C and adding that amount every decade so the stable period of 1981-2025 would be actually +1.3 C (+2.34 F) relative to what NYC might record in an unaltered "rural" state. 

Now some might instantly say, but NYC is in a megalopolis much larger than greater Toronto, would it not warm up even more? Perhaps, but as I said, past 100,000 the rate of increase is very slow and probably past 5 million it cannot increase because the environment is so substantially altered on a regional basis. The strength of the greater New York heat island is probably well over +1.5 F out into parts of west central NJ near the end of suburban sprawl. 

As to the urban park question and temperature reductions in hot weather, that probably washes out of data sets fairly quickly as there aren't all that many hot days and the nights in question remain more affected anyway. Urban heat islands tend to be something like 75% minimum boosts and 25% maximum boosts, an estimate of a +2.0 heat island really means +1.0 for average maximum and +3.0 for average minimum. Large stretches of cloudy wet weather show very small urban heat island effects, dry and clear months would have larger differentials. 

Growing up and spending summers in Greece I would visit my grandparents that lived JUST outside a small town (population ~5,000.) At the edge of the village/town it would turn into fields of open land and about 500 meters into the fields was my grandparents' home. 

Walking back from the town at night toward the house I could EASILY feel the temperature drop by several degrees once I would get to the edge. It was like walking into an air conditioned room. 

So I have first hand experience of a village or small town causing an obvious UHI even though people think a population center that small would be too insignificant to cause such an effect. 

[LibertyBell]

12 minutes ago, donsutherland1 said:

Tomorrow will be unseasonably cool. The mercury could struggle to reach 70° in New York City. It should rise into the lower 70s at Newark.

The chilly highs will challenge the record for lowest high temperatures two days after an 80° or above low at Central Park, JFK Airport, and Newark. The existing records are below:

Central Park: 71°, July 9, 1883
JFK Airport: 76°, July 23, 2019
Newark: 76°, July 23, 2019 

All of those readings followed lows of 80° two days earlier.

Central Park has had 72 lows of 80° or above; Newark has had 50; and, JFK Airport has had 16.

Temperatures will return mainly to the lower 80s for the remainder of June. Excessive heat does not appear likely to return in the near-term.

The ENSO Region 1+2 anomaly was +1.0°C and the Region 3.4 anomaly was 0.2°C for the week centered around June 18. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.47°C and the ENSO Region 3.4 anomaly has averaged -0.03°C. Neutral ENSO conditions will likely continue through at least late summer.

The SOI was +12.65 yesterday. 

The preliminary Arctic Oscillation (AO) was +1.073 today. 

Based on sensitivity analysis applied to the latest guidance, there is an implied 93% probability that New York City will have a warmer than normal June (1991-2020 normal). June will likely finish with a mean temperature near 73.1° (1.1° above normal). 

 

JFK Airport: 76°, July 23, 2019

 

Don was this after JFK's back to back 99 degree highs when they set a new heat index record??

[LibertyBell]

13 minutes ago, Sundog said:

Growing up and spending summers in Greece I would visit my grandparents that lived JUST outside a small town (population ~5,000.) At the edge of the village/town it would turn into fields of open land and about 500 meters into the fields was my grandparents' home. 

Walking back from the town at night toward the house I could EASILY feel the temperature drop by several degrees once I would get to the edge. It was like walking into an air conditioned room. 

So I have first hand experience of a village or small town causing an obvious UHI even though people think a population center that small would be too insignificant to cause such an effect. 

People need to stop creating concrete jungles, not only is it cooler outside of the city, it's also less polluted and much easier to sleep at night and breathe clean air with far lower rates of asthma.

[donsutherland1]

1 minute ago, LibertyBell said:

JFK Airport: 76°, July 23, 2019

 

Don was this after JFK's back to back 99 degree highs when they set a new heat index record??

Yes.

[bluewave]

1 hour ago, Roger Smith said:

But even by around 1890 to 1900 large cities were beginning to display an urban heat island.

Manhattan UHI peaked in 1910 right before the population density began to decline.