July 2025 Discussion-OBS - seasonable summer variability

[winterwarlock]

2 hours ago, LibertyBell said:

This might be the days of rain I saw on the forecast yesterday.  Sunday might be our last good day for awhile.

Im tired of this rain. Its like every late afternoon clouds up and rains...OK we get fri sat sun but you get my idea

 

Hasn't been a great summer for weather from Memorial Day on...yippee we get 3 days but it should be 6 days with rain chance after that

[steve392]

36 minutes ago, LibertyBell said:

Did we have less trees in the 40s, 50s and 60s when all those 100+ readings and 7+ day heatwaves were happening (as well as years like 1993 and 1999) or was there overgrowth because of the higher rainfall totals we have now? Maybe it's a combination of both? And more rainfall also means more water retention by the foliage which also makes for a slower temperature rise.

I agree we need to get the equipment out of that area.

We also need to remove some of these trees, I notice we have a lot of parasitic trees that really do not belong here. Tree of *Heaven* being a case in point.

 

 

I am going to say the tree's were saplings or new growth back then and are what are fully grown now for us.  So they probably did have less canopy cover providing shade.  

All the tree's in and around my neighborhood were all planted when the area was built right during WW2.

[Roger Smith]

2 hours ago, LibertyBell said:

The usual suspects are in the top 20, the summers I always talk about lol. Question though, why are we using 31 not 30? A month is scientifically speaking, the amount of time it takes for the moon to revolve around the earth and that averages out to 30 days (it's really 29.53 but we can round that to 30.)  

 

1. 1966 June 20 to July 20 ___________91.97

 2. 1993 July 5 to Aug 4 ______________91.61

 3. 1999 July 3 or 4 to Aug 2 or 3 ____ 90.94

 4. 1955 July 8 to Aug 7 ______________ 90.90

 5. 1944 July 22 to Aug 21 ___________ 90.84

 6. 1980 July 14 to Aug 13 ____________ 90.71

t7. 1988A July 16 to Aug 15 ___________ 90.29

t7. 2010 June 27 to July 27 __________ 90.29 (or July 3 to Aug 2 was also 90.29)

 9. 2005 July 15 to Aug 14 ___________ 89.87

10. 2011 July 4 to Aug 3 _____________ 89.84

11. 1983 July 11 to Aug 10 ____________ 89.71

12. 1952 June 24 to July 24 _________ 89.35

t13. 1977 July 13 to Aug 12 ___________ 89.29

t13. 1995 July 13 to Aug 12 ___________ 89.29

t15. 1876 June 23 to July 23 __________ 89.26

t15. 1991 June 24 to July 24 __________ 89.26

t15. 2006 July 11 to Aug 10 ____________89.26

18. 1949 July 13 to Aug 12 ____________ 89.13 __ a non-overlapping 31d interval June 11 to July 11 was 86.74

19. 1953 June 20 to July 20 __________ 88.90 __ non-overlapping 31d intervals Aug 8 (or 10) to Sep 7 (or 9) 87.00

20. 2002 Jul 20 or 22 to Aug 19 or 21_ 88.87 __ non-overlapping 31d interval June 20 or 21 to July 20 or 21 was 87.10

I used 31 days because July and August (and Dec Jan) are 31 day months and many of the records for calendar months are set in those months (not as many in winter given that Feb contributes more than June to lists of all-time record months). Our calendar has seven 31d months, four 30d and February (28 or 29). I can rerun the data and generate a list of top twenty 30-day averages, will hazard a guess it won't change a lot from the above. 

I went back into the table posted and fixed a few minor ranking errors after going back over my excel file generated list. Below 20th place (the portion you quoted) there are some 'B' 31-day intervals from various years. Each time one of those makes the list, the years below it are bumped down one rank if you were ranking years for their hottest 31-day interval (the B examples would not be in that list). 

[winterwx21]

51 minutes ago, winterwarlock said:

Im tired of this rain. Its like every late afternoon clouds up and rains...OK we get fri sat sun but you get my idea

 

Hasn't been a great summer for weather from Memorial Day on...yippee we get 3 days but it should be 6 days with rain chance after that

At least it's perfect timing though with 3 great days for the big holiday weekend. Even tomorrow with temps going into the low 90s, it won't feel bad out there with dewpoints only coming up a little to the low 60s. Couldn't have asked for a better 3 day holiday weekend. 

[Brian5671]

9 minutes ago, winterwx21 said:

At least it's perfect timing though with 3 great days for the big holiday weekend. Even tomorrow with temps going into the low 90s, it won't feel bad out there with dewpoints only coming up a little to the low 60s. Couldn't have asked for a better 3 day holiday weekend. 

Agreed, mostly dry outside of the severe weather the evening of 7/3

[steve392]

Outside of Friday, will this be the first Saturday AND Sunday that it hasn't rained in months???

[Roger Smith]

In terms of when does the hottest 31 day interval occur, this is the frequency of these intervals (* symbol means interval is matched by a later one, usually the next day is its starting point but differentials are noted of up to five days for 1899 (intervals starting July 2 and 7) and six days for 2010 (June 27 and July 3 start these)). 

Since this list includes the cooler half of the entries, we do find a few overlapping a calendar month. (June can only be 'all in' for May 31 to June 30 or June 1 to July 1, the first of those exists in the data for 1925). 

dur'n hottest 31d ___ Years include

May 31 - Jun 30 __ 1925

Jun 5 - Jul 5 _____ 1984

Jun 7 - Jul 7 _____ 1883

Jun 8 - Jul 8 _____ 1888, 2004

Jun 11 - Jul 11 ____ 1945

Jun 14 - Jul 14 ___ 1994

Jun 15 - Jul 15 ___ 1962, 1976

Jun 16 - Jul 16 ___ 2000

Jun 17 - Jul 17 ___ 1912

Jun 18 - Jul 18 ___ 1869, 1872, 1880, 1971

Jun 19 - Jul 19 ___ 1965* 1997

Jun 20 - Jul 20 __ 1904, 1907* 1908 1909, 1923* 1953 1964 1966

Jun 21 - Jul 21 ___ 1874, 1934*,

Jun 22 - Jul 22 __ 1946, 2017

Jun 23 - Jul 23 __ 1876, 1897, 2003, 2013

Jun 24 - Jul 24 __ 1875, 1898, 1901, 1922, 1952, 1991

Jun 25 - Jul 25 __ 1900, 1906, 2014

Jun 26 - Jul 26 __ 1878, 1889

Jun 27 - Jul 27 __ 2010* 2012* 2021

Jun 28 - Jul 28 __ 1881, 1910, 2018

Jun 29 - Jul 29 __ 1948, 2023

Jun 30 - Jul 30 __ 1887, 1903, 1913

July 1-31 _________ 1919, 1950

July 2 - Aug 1 ____ 1899* 1911, 1921, 1951, 1974, 2019, 2020

July 3 - Aug 2 ___ 1886, 1999

July 4 - Aug 3 ___ 1929, 1942, 1957, 2011

July 5 - Aug 4 ___ 1936, 1937, 1986, 1993, 

July 6 - Aug 5 ___ 1885, 1890*, 1928, 1934, 1982

July 7 - Aug 6 ___ 1879* 1899, 1981, 1989

July 8 - Aug 7 ___ 1905, 1955, 1967, 1992, 2008

July 9 - Aug 8 ___ 1954, 1960, 1987, 2007

July 10 - Aug 9 __ 1882, 1894, 1932, 1941, 1972

July 11 - Aug 10 __ 1870, 1924, 1927, 1930, 1931, 1943, 1968* 1979, 1983, 2006

July 12 - Aug 11 __ 1873, 1892, 1902, 2022

July 13 - Aug 12 __ 1893, 1896, 1917*, 1949, 1963, 1977, 1995, 1998

July 14 - Aug 13 __ 1980

July 15 - Aug 14 __ 1877, 1918, 1940, 2005

July 16 - Aug 15 __ 1926, 1975, 1985, 1988, 2016

July 17 - Aug 16 __ 1895

July 18 - Aug 17 __ 1990

July 19 - Aug 18 __ 1920, 2015

July 20 - Aug 19 __ 2002*

July 22 - Aug 21 __ 1937, 1944

July 23 - Aug 22 __ 1958, 1970

July 24 - Aug 23 __1939

July 25 - Aug 24 __1938

July 27 - Aug 26 __1947, 2009

July 29 - Aug 28 _ 1891

July 30 - Aug 29 _ 1871

July 31 - Aug 30 __2001

Aug 3 - Sep 2 ____ 1969

Aug 5 - Sep 4 ____ 1973

Aug 6 - Sep 5 ____ 1996

Aug 7 - Sep 6 ____ 1914, 1956, 1961

Aug 8 - Sep 7 ____ 1978

Aug 10 - Sep 9 ___ 1959

Aug 13 - Sep 12 __ 1884

(Aug 21 - Sep 20 1948 a secondary peak)

__________________

From the above it is clear that a large cluster of years are hottest from early July to early August. 

In 1991 intervals starting May 3 - June 2 averaged maximum of 80.0 + (this persisted to Aug 27 to Sep 26), the second earliest start for the 80+ season was 1962 (May 11 to Jun 10) but that summer ended a lot earlier as Aug 5 to Sep 4 was the last 80+ interval. 

The latest interval to average 80.0 or above was Sep 9 to Oct 8 1931, followed by Sep 7 to Oct 6, 1941 tied by 2005, then Sep 5 to Oct 5 1881. and tied fifth latest 1959, 1961 Sep 3 to Oct 2, then 1921 with Sep 2 to Oct 1. .. 2017 had 79.00 as late as Sep 11 to Oct 11. 

1895 began its 80+ season with May 21 to Jun 21, and ran to Aug 30-Sep 29 but there were late-summer gaps, no interval starting Aug 17 to 21 averaged 80+.

. 

[FPizz]

Shocked no one has brought up the central park sensor yet on page 13 of this thread.  Doh!

[Brian5671]

42 minutes ago, steve392 said:

Outside of Friday, will this be the first Saturday AND Sunday that it hasn't rained in months???

streak looks to finally end here-we've gone since 3/22 without a rainfree weekend...granted a few were .01 or .05 

[bluewave]

3 hours ago, LibertyBell said:

Did we have less trees in the 40s, 50s and 60s when all those 100+ readings and 7+ day heatwaves were happening (as well as years like 1993 and 1999) or was there overgrowth because of the higher rainfall totals we have now? Maybe it's a combination of both? And more rainfall also means more water retention by the foliage which also makes for a slower temperature rise.

I agree we need to get the equipment out of that area.

We also need to remove some of these trees, I notice we have a lot of parasitic trees that really do not belong here. Tree of *Heaven* being a case in point.

 

 

Absolutely. Just compare the old photos of the site from the recent ones. Most of those 100° readings from the 1930s into the early 1990s would have only been mid to upper 90s if the they had the same tree cover back then.

The strongest wind gust is still 78 mph set back in December of 1974 when the trees were much lower. So there could have been higher gusts in the interim but the tress could be interfering like with the temperatures.
 

 

 

[Sundog]

26 minutes ago, FPizz said:

Shocked no one has brought up the central park sensor yet on page 13 of this thread.  Doh!

I'm working on an extensive post regarding the issue

[nycwinter]

since when are temps taken at airports like newark and laguardia really accurate  compared to central park..

[steve392]

Is the air quality alerts because of all the fire works smoke?

[winterwarlock]

So what's the deal with Chantals waste..is this a serious threat for heavy rain..surprised  this board is crickets

[Brian5671]

9 minutes ago, winterwarlock said:

So what's the deal with Chantals waste..is this a serious threat for heavy rain..surprised  this board is crickets

models don't have all that much-maybe .50 to 1.00.   It will come down to how it interacts with an incoming cold front.    But seems like in and out-not sure where this days and days of rain is coming from.

-

[winterwarlock]

Just now, Brian5671 said:

models don't have all that much-maybe .50 to 1.00.   It will come down to how it interacts with an incoming cold front.    But seems like in and out-not sure where this days and days of rain is coming from.

That's what I'm worried about..models and mets have been all over the map this year...days that are forecasted less seem to ovrrperform and vice versa

[Wannabehippie]

7 hours ago, LibertyBell said:

Just get the equipment out of Central Park and the problem is solved.  Government needs to step in since NWS won't do a thing.

 

 

7 hours ago, LibertyBell said:

This is why I advocate for the heliport (KJRB peaked at 105 in June).  Besides the heliport, we can use rooftop stations.  They would definitely be hotter than the shaded areas you speak of.

 

Wouldn't rooftop stations give us inaccurate readings due to elevation?

[Dark Star]

3 hours ago, Wannabehippie said:

 

Wouldn't rooftop stations give us inaccurate readings due to elevation?

Rooftops are usually like driveways, much hotter than the grass surfaces.   

[psv88]

87 today

[SACRUS]

Highs:
 

 

EWR: 90
LGA: 88
TEB: 88 
PHL: 88
New Brnswck: 87
JFK: 86
TTN: 86
ACY: 86
BLM: 85 ** missing hourly/intra hours
ISP: 84

NYC: 84

[bluewave]

18 hours ago, winterwarlock said:

Im tired of this rain. Its like every late afternoon clouds up and rains...OK we get fri sat sun but you get my idea

 

Hasn't been a great summer for weather from Memorial Day on...yippee we get 3 days but it should be 6 days with rain chance after that

Higher dew points and more clouds with onshore flow mean more rain chances. So your area usually sees at least 30-40 days reaching 90° each season. But the chances of going 20 straight days reaching 90° like in 1988 when it was much drier without interruption are very low. But the overall 90° day counts in NJ are much higher than the 1980s and 1990s. Just no really long extended heatwaves. So a bunch of shorter heatwaves giving you more total 90° days than you used to get. 

[LongBeachSurfFreak]

12 hours ago, Wannabehippie said:

 

Wouldn't rooftop stations give us inaccurate readings due to elevation?

Allot of would depend on just how high of a rooftop. I would love to see obs from the top of the Nordstrom tower at 1550’. (Highest flat roof in nyc) 

Probably averages double the snowfall of the park. Not only a few degrees cooler due to height but also high enough to be out of the heat island near the ground. 

[bluewave]

9 minutes ago, LongBeachSurfFreak said:

Allot of would depend on just how high of a rooftop. I would love to see obs from the top of the Nordstrom tower at 1550’. (Highest flat roof in nyc) 

Probably averages double the snowfall of the park. Not only a few degrees cooler due to height but also high enough to be out of the heat island near the ground. 

Just look at all the new mesonet sites that have multiple elevation temperature observations. Temperatures most times decline with elevation from 2m to 10m and 30m to over 100m at some sites. The exceptions are during radiational cooling inversions and strong winter WAA when the higher levels warm more than the surface and we get fog.

[steve392]

69 degree's this morning!

[wdrag]

No thread, at least not yet...  but the week ahead seems like opportunity for mesoscale excesses.  Many models disagree with the EPS (and occasionally the CMC suite)  ever increasing heavy rain threat for parts of our NNJ portion of the NYC subforum.  For now will go with 3" max Mon afternoon-evening somewhere up here-probably near I95.  (Chantel 850 flow-moisture advection combined with RRQ of th UL jet over New England)

Looking ahead...the CF heavy convection in parts of the area Tue.  

Then Thu-Fri, maybe Sat... heavy rain potential with southern stream short wave and warm front returning.  Some of the experimental modeling has us in small chance iso FF THU-Sat (spot 5"+ this 3 day period). 

Added July CoCoRaHs totals as a baseline.  Click for clarity.

Next potential 3 day (dry) haying period around 7/16-19? 

 

Cleaned up the FF potential graphics at 752AM

 

 

[SACRUS]

75 / 65 sunny and hot low - mid 90s in the hot areas today.  Messy period overall warm - hot / humid and wetter starting tomorrow.  Under the northern ridge, western ridge pushing out spurts of heat and the W atl ridge expanding west enough to pump heights the next 7 - 9 days.   Clouds from Chantal may get here as early as Mon morning, otherwise more 80s - low 90s Monday.   Rain / storm chance look to focus on Mon PM, / Tue AM , Thu- Sat.  Clouds the caveat in pushing 90s, onshore along the coast keeps heat focused west.   Hotter by mid month with ridge building height and heat expanding east.

 

7/7 - 7/15 : Warm - hot , humid, wetter / onshore at times heat focused inland, clouds /storms frequent
7/16 - beyond :  Hotter

 

[SACRUS]

 

Records:

Highs:

EWR: 103 (2010)
NYC: 103 (2010)
LGA: 103 (2010)
JFK: 101 (2010)
New Brnswck: 103 (1999)


Lows:

EWR: 54 (1979)
NYC: 53 (1979)
LGA: 56 (1979)
JFK: 56 (1979)
New Brnswck: 48 (1979)


Historical:

1879: Boston, MA recorded its lowest temperature of 50 °F for the month of July. (Ref. NOAA Boston Weather Events)

1893 - A violent tornado killed 71 persons on its forty-mile track across northwestern Iowa. Forty-nine persons were killed around Pomeroy, where eighty percent of the buildings were destroyed, with most leveled to the ground. Photos showed most of the town without a wall or tree left standing. (The Weather Channel)


1928: A seven-inch hailstone weighing 1.5 pounds fell in Potter Nebraska. With a circumference of 17 inches, this appeared to be the largest hailstone in the world at that time.

1928 - A hailstorm at Potter, NE, produced a stone which was 5.5 inches in diameter, and seventeen inches in circumference, weighing a pound and a half. (David Ludlum)


1936: The temperature at Moorhead, MN, soared to 114 °F to establish a new state record and the temperature at Steel, ND, soared to 121 °F to establish a new state record  (Ref. Lowest and Highest Temperatures for the 50 States)

1972: Unusually strong Canadian high pressure pushed a cold front into the central Gulf of Mexico bringing record chill to the central states. Richland Center, WI and St. Louis, MO set July record lows of 38° and 51° respectively. Other daily records: Lansing, MI: 39°, Detroit, MI: 42°, Columbus, OH: 43°, Toledo, OH: 43°, Dayton, OH: 44°, Springfield, MO: 44°, Peoria, IL: 48°, Springfield, IL: 48°,Lexington, KY: 49 °F. (Ref. Additional Temperatures Listed On This Link)

1977:  RIC The Highest temperature ever recorded for July was 105 °F which has occurred on two other dates. (Ref. Richmond Weather Records - KRIC)

1978: Severe thunderstorms developed over eastern South Dakota during the afternoon and moved quickly to the northeast. Winds of up to 80 mph were reported and hail as big as baseballs pounded some areas. A tornado produced widespread damage to crops and personal property across Turner and Lincoln counties. Total property and crop damage from the storms was near $20 million dollars.(Ref. Wilson Wx. History)

1982: A severe thunderstorm which produced extremely high winds pummeled Sioux Falls, SD. The thunderstorm produced winds of 125 mph which swept across the city causing damage in a path ten blocks wide and three miles long. The National Weather Service office at the airport reported a gust of 82 mph. (Ref. Wilson Wx. History)

1983: Cool high pressure settled over the Great Lakes bringing record lows. The 41° at Grand Rapids, MI is the lowest ever recorded during the month of July. Chicago, IL set a daily record low with 46° and the low of 45° the next morning set the record low for July. Other daily record lows included: Ste. St. Marie, MI: 36°, Muskegon, MI: 41° and La Crosse, WI: 48°. (Ref. Wilson Wx. History)

1985 - Lightning struck a large transformer in Salt Lake County sending a 200 foot fireball into the air and blacking out almost the entire state for up to five hours. (The Weather Channel)

1986 - Thunderstorm rains during the mid morning hours, and again during the evening, produced major flash-flooding at Leavenworth, KS. The official rainfall total was 10.37 inches, but unofficial totals exceeded twelve inches. At nearby Kansas City, the rainfall total of 5.08 inches was a daily record for July. (Storm Data)

1987 - Thunderstorms produced severe weather in twenty-one states east of the Rockies, with severe weather reported in Kentucky and Indiana for the second day in a row. A thunderstorm produced more than five inches of rain in one hour near Reynolds, IL. Rochester, NY, was soaked with 3.25 inches, a record 24 hour total for the month of July. (The National Weather Summary) (Storm Data)

1988 - Thirty-six cities in the north central and northeastern U.S. reported record high temperatures for the date. Afternoon highs of 98 degrees at International Falls, MN, and 101 degrees at Flint, MI, equalled all-time records. Highs of 96 degrees at Muskegon, MI, and 97 degrees at Buffalo, NY, were records for July. (The National Weather Summary)

1989 - Unseasonably hot weather prevailed in the southwestern U.S. Ten cities reported record high temperatures for the date, including Las Vegas, NV, with a reading of 115 degrees. Hanksville, UT, reached 112 degrees, Bullhead City, AZ, hit 120 degrees, and Death Valley, CA, soared to 126 degrees. (The National Weather Summary)


1996: The hottest July temperature ever recorded in Oklahoma City, OK is 110°.  (Ref. Wilson Wx. History)

1999 : Record heat occurred across the Mid-Atlantic and Northeast. Record highs for the date included: Washington, DC: 103°, Raleigh-Durham, NC: 102°, Newark, NJ: 102°, Harrisburg, PA: 102°, Baltimore, MD: 101°, NYC-Central Park, NY: 101°, NYC-LaGuardia, NY: 101°, Salisbury, MD: 100°, Roanoke, VA: 100°, Allentown, PA: 100°, Reading, PA: 100°, Trenton, NJ: 100°, Atlantic City, NJ: 99°, NYC-Kennedy, NY: 99°, Hartford, CT: 99°, Lynchburg, VA: 98°, Philadelphia, PA: 98 °F. (Ref. Additional Temperatures Listed On This Link)

2006: From June 22nd to July 6th a total of 15.52 inches of rain occurred averaging more than one inch a day over one-half of a summer month period, amazing! (Ref. Annandale Weather Records)

2007: Death Valley, California: Death Valley reaches 129°F the fourth time it has been so hot at this site since 1913. (Ref. WxDoctor)

2009: In Twisp, WA, a couple took shelter in a car due to a thunderstorm. Lightning struck the car and blew out 2 of its tires. After the incident, the engine would not start. The couple was unhurt. (Weather Guide Calendar with Phenomenal Weather Events 2011 Accord Pub. 2010, USA)

2010: On the 6th, BWI soared to 105 °F; 2nd hottest day ever in Baltimore (107 °F, 7/10/36); at or above 100 °F at BWI on 5 days, most on record. BWI recorded record high temperatures on 4 days: 6th (105 °F), 7th (101 °F), 24th (101 °F) and 25th (100 °F). DCA soared to a record 102 °F on the 7th and 101 °F on the 24th. Ref. July PRESTO Page 1

[SACRUS]

 

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[SACRUS]