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July 2025 Discussion-OBS - seasonable summer variability


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1 hour ago, donsutherland1 said:

July 2025 ranked among the 10 hottest Julys on record in the greater New York City area:

Monthly Mean Temperatures:

Bridgeport: 78.2° (5th hottest)
Islip: 78.5° (2nd hottest)
New York City-Central Park: 79.5° (tied 14th hottest)
New York City-JFK Airport: 79.9° (2nd hottest)
New York City-LaGuardia Airport: 81.0° (8th hottest)
Newark: 82.1° (5th hottest)

Notes: The 0.4° difference between JFK Airport and Central Park when JFK Airport had a higher mean temperature in July was the largest such difference on record. Adjusting for the trees would have led to a mean temperature near 80.0° in Central Park. That would have tied for 8th hottest. 

image.thumb.png.5d4697d6b7a193bd865398a103e8dabd.png

Amazing that the area that has changed very little around JFK (the houses were already built and have basically stayed the same) had the biggest departure in terms of ranking the hottest July. 

Obviously it's a combination of factors but the above normal ocean temps and outrageous dewpoint temps played their role and kept JFK from cooling down as much as they could have in the past. Same in Islip. 

I guess UHI warmed up the whole damn ocean! 

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Warmest July on record at HVN,FWN,DXR,MTP, and the Charlotteburg Reservior. 2nd warmest finish at HPN and ISP. SMQ had their 3rd warmest July and highest average maximum daily dew point at 74.3°. FWN also had their highest average maximum dew point at 72.3°. JFK had their 2nd highest average maximum dew point at 73.2° behind the record of 74.2° in 2019. So a continuation of the shift to Mid-Atlantic dew points during  summers over the last decade. 
 

Time Series Summary for CHARLOTTEBURG RESERVOIR, NJ - Month of Jul
Click column heading to sort ascending, click again to sort descending.
1 2025 77.0 2
2 2020 76.1 0
3 2024 75.8 0
4 2019 75.4 0
5 1935 75.3 6
6 2010 75.1 0
7 2013 75.0 3
- 1894 75.0 8
8 1955 74.9 2
9 2023 74.3 0
- 2022 74.3 0
10 2008 74.2 16
- 1949 74.2 0

 

Time Series Summary for NEW HAVEN TWEED AP, CT - Month of Jul
Click column heading to sort ascending, click again to sort descending.
1 2025 78.8 0
2 2013 78.6 0
3 2024 78.3 0
- 2020 78.3 0
4 2022 78.1 0
5 2023 78.0 1
6 2019 77.9 0
7 2010 77.3 0
8 2012 76.6 0
9 2011 76.4 0
10 2008 75.9 0


 

Time Series Summary for SUSSEX AIRPORT, NJ - Month of Jul
Click column heading to sort ascending, click again to sort descending.
1 2025 76.9 0
2 2020 76.5 0
3 2024 75.7 0
4 2019 75.3 0
5 2023 74.8 0
6 2013 74.6 0
7 2011 74.5 0
8 2022 74.4 0
9 2012 74.3 0
- 2006 74.3 0
10 2010 74.1 2

 

Time Series Summary for DANBURY MUNICIPAL AP, CT - Month of Jul
Click column heading to sort ascending, click again to sort descending.
1 2025 77.1 0
2 1999 76.4 8
3 2024 76.1 1
- 2023 76.1 0
4 2022 75.9 0
5 2013 75.7 0
6 2020 75.6 0
7 2010 74.7 0
8 2019 74.6 0
9 2012 74.1 0
10 2011 74.0 0

 

Time Series Summary for MONTAUK AIRPORT, NY - Month of Jul
Click column heading to sort ascending, click again to sort descending.
1 2025 77.0 3
2 2024 76.7 1
3 2023 76.5 2
4 2013 76.1 0
5 2020 75.9 0
- 2010 75.9 0
6 2022 75.5 0
- 2011 75.5 0
7 2019 75.1 0
8 2015 74.9 0
9 2012 74.7 0
10 2006 74.6 0

 

Time Series Summary for WESTCHESTER CO AP, NY - Month of Jul
Click column heading to sort ascending, click again to sort descending.
1 1999 78.5 1
2 2025 77.3 1
3 2013 77.0 0
- 2010 77.0 0
4 2020 76.9 0
5 2022 76.8 0
- 2019 76.8 0
6 1966 76.7 0
- 1955 76.7 2
7 2024 76.6 0
- 2011 76.6 1
8 2012 76.4 0
9 2016 76.3 0

 

Time Series Summary for ISLIP-LI MACARTHUR AP, NY - Month of Jul
Click column heading to sort ascending, click again to sort descending.
1 1999 78.6 0
2 2025 78.5 0
3 2019 78.1 0
4 2013 78.0 0
- 2010 78.0 0
5 2020 77.7 0
6 2011 77.6 0
7 1994 77.3 0
8 2022 77.1 0
9 2023 77.0 0
10 2024 76.9 0

 

Time Series Summary for SOMERSET AIRPORT, NJ - Month of Jul
Click column heading to sort ascending, click again to sort descending.
1 1999 78.5 1
2 2024 78.3 0
3 2025 78.0 0
- 2020 78.0 0
4 2022 77.9 0
5 2019 77.5 0
- 2011 77.5 0
6 2013 77.4 0
7 2012 76.9 0
8 2023 76.8 0
- 2003 76.8 25
9 2016 76.7 0
- 2010 76.7 0
10 2006 76.4 0
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2 hours ago, donsutherland1 said:

July 2025 ranked among the 10 hottest Julys on record in the greater New York City area:

Monthly Mean Temperatures:

Bridgeport: 78.2° (5th hottest)
Islip: 78.5° (2nd hottest)
New York City-Central Park: 79.5° (tied 14th hottest)
New York City-JFK Airport: 79.9° (2nd hottest)
New York City-LaGuardia Airport: 81.0° (8th hottest)
Newark: 82.1° (5th hottest)

Notes: The 0.4° difference between JFK Airport and Central Park when JFK Airport had a higher mean temperature in July was the largest such difference on record. Adjusting for the trees would have led to a mean temperature near 80.0° in Central Park. That would have tied for 8th hottest. 

image.thumb.png.5d4697d6b7a193bd865398a103e8dabd.png

ugh JFK should be given 80.0, it didn't go below 80.0 until after sunset, it was basically August by then, Don

 

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2 hours ago, donsutherland1 said:

July 2025 ranked among the 10 hottest Julys on record in the greater New York City area:

Monthly Mean Temperatures:

Bridgeport: 78.2° (5th hottest)
Islip: 78.5° (2nd hottest)
New York City-Central Park: 79.5° (tied 14th hottest)
New York City-JFK Airport: 79.9° (2nd hottest)
New York City-LaGuardia Airport: 81.0° (8th hottest)
Newark: 82.1° (5th hottest)

Notes: The 0.4° difference between JFK Airport and Central Park when JFK Airport had a higher mean temperature in July was the largest such difference on record. Adjusting for the trees would have led to a mean temperature near 80.0° in Central Park. That would have tied for 8th hottest. 

image.thumb.png.5d4697d6b7a193bd865398a103e8dabd.png

adjusting for calendar BS, JFK was definitely at or above 80.0

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34 minutes ago, Sundog said:

Amazing that the area that has changed very little around JFK (the houses were already built and have basically stayed the same) had the biggest departure in terms of ranking the hottest July. 

Obviously it's a combination of factors but the above normal ocean temps and outrageous dewpoint temps played their role and kept JFK from cooling down as much as they could have in the past. Same in Islip. 

I guess UHI warmed up the whole damn ocean! 

that JFK number is BS, it was definitely at or above 80.0

I don't subscribe to this antiquated idea that the new day begins at midnight/1 am.

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18 minutes ago, bluewave said:

Warmest July on record at HVN,FWN,DXR,MTP, and the Charlotteburg Reservior. 2nd warmest finish at HPN and ISP. SMQ had their 3rd warmest July and highest average maximum daily dew point at 74.3°. FWN also had their highest average maximum dew point at 72.3°. JFK had their 2nd highest average maximum dew point at 73.2° behind the record of 74.2° in 2019. So a continuation of the shift to Mid-Atlantic dew points during  summers over the last decade. 
 

Time Series Summary for CHARLOTTEBURG RESERVOIR, NJ - Month of Jul
Click column heading to sort ascending, click again to sort descending.
1 2025 77.0 2
2 2020 76.1 0
3 2024 75.8 0
4 2019 75.4 0
5 1935 75.3 6
6 2010 75.1 0
7 2013 75.0 3
- 1894 75.0 8
8 1955 74.9 2
9 2023 74.3 0
- 2022 74.3 0
10 2008 74.2 16
- 1949 74.2 0

 

Time Series Summary for NEW HAVEN TWEED AP, CT - Month of Jul
Click column heading to sort ascending, click again to sort descending.
1 2025 78.8 0
2 2013 78.6 0
3 2024 78.3 0
- 2020 78.3 0
4 2022 78.1 0
5 2023 78.0 1
6 2019 77.9 0
7 2010 77.3 0
8 2012 76.6 0
9 2011 76.4 0
10 2008 75.9 0


 

Time Series Summary for SUSSEX AIRPORT, NJ - Month of Jul
Click column heading to sort ascending, click again to sort descending.
1 2025 76.9 0
2 2020 76.5 0
3 2024 75.7 0
4 2019 75.3 0
5 2023 74.8 0
6 2013 74.6 0
7 2011 74.5 0
8 2022 74.4 0
9 2012 74.3 0
- 2006 74.3 0
10 2010 74.1 2

 

Time Series Summary for DANBURY MUNICIPAL AP, CT - Month of Jul
Click column heading to sort ascending, click again to sort descending.
1 2025 77.1 0
2 1999 76.4 8
3 2024 76.1 1
- 2023 76.1 0
4 2022 75.9 0
5 2013 75.7 0
6 2020 75.6 0
7 2010 74.7 0
8 2019 74.6 0
9 2012 74.1 0
10 2011 74.0 0

 

Time Series Summary for MONTAUK AIRPORT, NY - Month of Jul
Click column heading to sort ascending, click again to sort descending.
1 2025 77.0 3
2 2024 76.7 1
3 2023 76.5 2
4 2013 76.1 0
5 2020 75.9 0
- 2010 75.9 0
6 2022 75.5 0
- 2011 75.5 0
7 2019 75.1 0
8 2015 74.9 0
9 2012 74.7 0
10 2006 74.6 0

 

Time Series Summary for WESTCHESTER CO AP, NY - Month of Jul
Click column heading to sort ascending, click again to sort descending.
1 1999 78.5 1
2 2025 77.3 1
3 2013 77.0 0
- 2010 77.0 0
4 2020 76.9 0
5 2022 76.8 0
- 2019 76.8 0
6 1966 76.7 0
- 1955 76.7 2
7 2024 76.6 0
- 2011 76.6 1
8 2012 76.4 0
9 2016 76.3 0

 

Time Series Summary for ISLIP-LI MACARTHUR AP, NY - Month of Jul
Click column heading to sort ascending, click again to sort descending.
1 1999 78.6 0
2 2025 78.5 0
3 2019 78.1 0
4 2013 78.0 0
- 2010 78.0 0
5 2020 77.7 0
6 2011 77.6 0
7 1994 77.3 0
8 2022 77.1 0
9 2023 77.0 0
10 2024 76.9 0

 

Time Series Summary for SOMERSET AIRPORT, NJ - Month of Jul
Click column heading to sort ascending, click again to sort descending.
1 1999 78.5 1
2 2024 78.3 0
3 2025 78.0 0
- 2020 78.0 0
4 2022 77.9 0
5 2019 77.5 0
- 2011 77.5 0
6 2013 77.4 0
7 2012 76.9 0
8 2023 76.8 0
- 2003 76.8 25
9 2016 76.7 0
- 2010 76.7 0
10 2006 76.4 0

July 2010 was hotter but with a lower dew point?

 

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3 hours ago, bluewave said:

Warmest July on record at HVN,FWN,DXR,MTP, and the Charlotteburg Reservior. 2nd warmest finish at HPN and ISP. SMQ had their 3rd warmest July and highest average maximum daily dew point at 74.3°. FWN also had their highest average maximum dew point at 72.3°. JFK had their 2nd highest average maximum dew point at 73.2° behind the record of 74.2° in 2019. So a continuation of the shift to Mid-Atlantic dew points during  summers over the last decade. 
 

Time Series Summary for CHARLOTTEBURG RESERVOIR, NJ - Month of Jul
Click column heading to sort ascending, click again to sort descending.
1 2025 77.0 2
2 2020 76.1 0
3 2024 75.8 0
4 2019 75.4 0
5 1935 75.3 6
6 2010 75.1 0
7 2013 75.0 3
- 1894 75.0 8
8 1955 74.9 2
9 2023 74.3 0
- 2022 74.3 0
10 2008 74.2 16
- 1949 74.2 0

 

Time Series Summary for NEW HAVEN TWEED AP, CT - Month of Jul
Click column heading to sort ascending, click again to sort descending.
1 2025 78.8 0
2 2013 78.6 0
3 2024 78.3 0
- 2020 78.3 0
4 2022 78.1 0
5 2023 78.0 1
6 2019 77.9 0
7 2010 77.3 0
8 2012 76.6 0
9 2011 76.4 0
10 2008 75.9 0


 

Time Series Summary for SUSSEX AIRPORT, NJ - Month of Jul
Click column heading to sort ascending, click again to sort descending.
1 2025 76.9 0
2 2020 76.5 0
3 2024 75.7 0
4 2019 75.3 0
5 2023 74.8 0
6 2013 74.6 0
7 2011 74.5 0
8 2022 74.4 0
9 2012 74.3 0
- 2006 74.3 0
10 2010 74.1 2

 

Time Series Summary for DANBURY MUNICIPAL AP, CT - Month of Jul
Click column heading to sort ascending, click again to sort descending.
1 2025 77.1 0
2 1999 76.4 8
3 2024 76.1 1
- 2023 76.1 0
4 2022 75.9 0
5 2013 75.7 0
6 2020 75.6 0
7 2010 74.7 0
8 2019 74.6 0
9 2012 74.1 0
10 2011 74.0 0

 

Time Series Summary for MONTAUK AIRPORT, NY - Month of Jul
Click column heading to sort ascending, click again to sort descending.
1 2025 77.0 3
2 2024 76.7 1
3 2023 76.5 2
4 2013 76.1 0
5 2020 75.9 0
- 2010 75.9 0
6 2022 75.5 0
- 2011 75.5 0
7 2019 75.1 0
8 2015 74.9 0
9 2012 74.7 0
10 2006 74.6 0

 

Time Series Summary for WESTCHESTER CO AP, NY - Month of Jul
Click column heading to sort ascending, click again to sort descending.
1 1999 78.5 1
2 2025 77.3 1
3 2013 77.0 0
- 2010 77.0 0
4 2020 76.9 0
5 2022 76.8 0
- 2019 76.8 0
6 1966 76.7 0
- 1955 76.7 2
7 2024 76.6 0
- 2011 76.6 1
8 2012 76.4 0
9 2016 76.3 0

 

Time Series Summary for ISLIP-LI MACARTHUR AP, NY - Month of Jul
Click column heading to sort ascending, click again to sort descending.
1 1999 78.6 0
2 2025 78.5 0
3 2019 78.1 0
4 2013 78.0 0
- 2010 78.0 0
5 2020 77.7 0
6 2011 77.6 0
7 1994 77.3 0
8 2022 77.1 0
9 2023 77.0 0
10 2024 76.9 0

 

Time Series Summary for SOMERSET AIRPORT, NJ - Month of Jul
Click column heading to sort ascending, click again to sort descending.
1 1999 78.5 1
2 2024 78.3 0
3 2025 78.0 0
- 2020 78.0 0
4 2022 77.9 0
5 2019 77.5 0
- 2011 77.5 0
6 2013 77.4 0
7 2012 76.9 0
8 2023 76.8 0
- 2003 76.8 25
9 2016 76.7 0
- 2010 76.7 0
10 2006 76.4 0

Wow, since 1970, July nighttime low temperatures at NYC have risen 3.1F, while lows at Charlotteburg Reservoir have risen 7.1F, per linear regression.

oFATegE.png

maHWYLU.png

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Just now, TheClimateChanger said:

Wow, since 1970, July nighttime low temperatures at NYC have risen 3.1F, while lows at Charlotteburg Reservoir have risen 7.1F, per linear regression.

oFATegE.png

maHWYLU.png

You can even see the point where atmospheric changes start to swamp out the UHI signal. From 1970-2000, both sites show a small cooling trend, with NYC lows dropping 0.2F, while the Charlotteburg site saw lows drop by 0.7F during that timeframe. Hard to tell if the late 20th century cooling is a real trend or just an artifact from changing equipment/observation practices and site location. I'm not sure if that cooling trend is real or just manufactured by those non-climatic factors.

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13 minutes ago, TheClimateChanger said:

You can even see the point where atmospheric changes start to swamp out the UHI signal. From 1970-2000, both sites show a small cooling trend, with NYC lows dropping 0.2F, while the Charlotteburg site saw lows drop by 0.7F during that timeframe. Hard to tell if the late 20th century cooling is a real trend or just an artifact from changing equipment/observation practices and site location. I'm not sure if that cooling trend is real or just manufactured by those non-climatic factors.

it's not really cooling, maxes have stabilized while mins are climbing so overall it's still warming.

 

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10 minutes ago, LibertyBell said:

it's not really cooling, maxes have stabilized while mins are climbing so overall it's still warming.

 

Wow, I don't agree with this statement at all. Recent Julys have had mean minimum temperatures that are warmer than the mean 24-hour averages from past "cold" Julys. Probably after 2050, we will begin to see Julys where the mean minimum temperatures exceed the mean maximum temperatures from old-school cold Julys. For some reason, you only ever look and compare to the hottest years?

For example, JFK's mean minimum last month was 72.7F. That exceeds the mean 24-hour average of 71.8F in 1956, 72.2F in 1996, 72.2F in 1965, 72.3F in 2000, 72.4F in 2001, and falls just shy of the 72.8F observed in 1976. It's probably just a handful of decades before JFK starts seeing low temperatures in July that exceed the mean maximum temperatures observed in cold Julys (e.g., 1956, 77.9F; 1996, 78.6F; 2000, 79.5F; and 1967, 79.7F). I don't think its too hard to imagine a future in 2060 where NYC looks more like Washington, DC of 2000-2020, where such low temperatures are common.

I think it's significant when low temperatures are exceeding the mean of high and low from many past years. In the first 6 years after installation of the ASOS at JFK, there were 3 years in which the month of July had a colder mean temperature than this year's mean low temperature (1996, 2000, and 2001).

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1 hour ago, TheClimateChanger said:

Wow, since 1970, July nighttime low temperatures at NYC have risen 3.1F, while lows at Charlotteburg Reservoir have risen 7.1F, per linear regression.

oFATegE.png

maHWYLU.png

Well Charlotteburg is the biggest city in the country, after all. 

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1 hour ago, TheClimateChanger said:

Wow, I don't agree with this statement at all. Recent Julys have had mean minimum temperatures that are warmer than the mean 24-hour averages from past "cold" Julys. Probably after 2050, we will begin to see Julys where the mean minimum temperatures exceed the mean maximum temperatures from old-school cold Julys. For some reason, you only ever look and compare to the hottest years?

For example, JFK's mean minimum last month was 72.7F. That exceeds the mean 24-hour average of 71.8F in 1956, 72.2F in 1996, 72.2F in 1965, 72.3F in 2000, 72.4F in 2001, and falls just shy of the 72.8F observed in 1976. It's probably just a handful of decades before JFK starts seeing low temperatures in July that exceed the mean maximum temperatures observed in cold Julys (e.g., 1956, 77.9F; 1996, 78.6F; 2000, 79.5F; and 1967, 79.7F). I don't think its too hard to imagine a future in 2060 where NYC looks more like Washington, DC of 2000-2020, where such low temperatures are common.

I think it's significant when low temperatures are exceeding the mean of high and low from many past years. In the first 6 years after installation of the ASOS at JFK, there were 3 years in which the month of July had a colder mean temperature than this year's mean low temperature (1996, 2000, and 2001).

I think you misread what I wrote: what you stated here is what I said, the mins are rapidly increasing, the maxes are not rapidly increasing, they are relatively stable (it could be a small increase but not anything like the rapid rate of the mins increase.) So the daily range is much less (the difference between min and max.)  I don't disagree with what you wrote about 2050 either, it's just that we are not there yet.

 

Recent Julys have had mean minimum temperatures that are warmer than the mean 24-hour averages from past "cold" Julys. Probably after 2050, we will begin to see Julys where the mean minimum temperatures exceed the mean maximum temperatures from old-school cold Julys.

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