LibertyBell

mean temps have no real connection to extreme highs, during the summer mean temps are mostly driven by elevated mins, we have the same thing going on here.

good point about the 60s-80s but the 30s-50s period might be part of a cycle and when it repeats it will be even hotter....also much drier back then. The atmosphere is taking on the properties of water in terms of specific heat with how humid and wet it's become lol

but that doesn't explain that huge spike during the 30s, 40s and 50s and then we dipped during the 60s, 70s and 80s when the equipment was still properly sited.

It also left out the huge spike during the 1930s-1950s period

Yes this is why our summer heat hasn't been as extreme as it was during the 1930s-1950s and during the 1990s either.

I know but the number of 100 degree days from the 1930s through the 1950s and the number of years with 100 degree days is far in excess of anything we had before or since so that is probably cyclical, I wonder when we will see a return to that kind of heat again?

They should have done a tally by decade, so I'll try to do that myself. Number of 100+ days per decade / number of years with 100+ days per decade 1880s : 1 / 1 1890s : 1 / 1 1900s : 2 / 1 1910s : 3 / 3 1920s : 2 / 2 1930s : 8 / 5 1940s : 8 / 3 1950s : 12 / 5 1960s : 4 / 1 1970s : 3 / 1 1980s : 2 / 1 1990s : 8 / 4 2000s : 1 / 1 2010s : 5 / 3 Doing this tally I'm a little shocked how many 100 degree days had between the 1930s and the 1950s and despite the enormous exception of 1966 which had 4 of them (the only 4 of that entire decade!) a big downturn in 100+ degree days began during the 1960s which only spiked again in the 1990s before resuming the downward trend. The early 2010s were an exception of course. There is obviously something cyclical going on here. No other way to explain what happened during the 1930s-1950s period. And how quiet it was both before and after that. And look at how both the 1930s and the 1950s had half of their years (5) hitting 100+ -- that has never been matched either!

eh to be fair Chris, 50% more is somewhat more than slight (9 to 6) 1993 had slightly more than 1949 did though (9 to 8)

and 1949 somehow had 8 in EWR and 5 99+ days at NYC, wow

Here are all of NYC 100+ days. I find it somewhat ironic that the first recorded 100 degree day (in 1881) was also the latest it's ever happened, 101 on September 7th. https://www.weather.gov/media/okx/Climate/CentralPark/100DegreeDays.pdf 100 Degree Day Information at Central Park (1869 to Present) Last Updated: 1/22/25 100 Degree Facts * Highest Ever Recorded: 106 on July 9, 1936 Most Days by Month: June 3 + July 42 + August 13 + September 2 = Total 60 days Most in one year: 4 (1966 and 1953) Most consecutive 100 degree days: 3 July 8-10, 1993 & August 26-28, 1948 Last time had 100 degree day in September: the 2nd in 1953 (102) Last time had 100 degree day in August: the 9th in 2001 (103) Last time had 100 degree day in July: the 18th in 2012 (100) Last time had 100 degree day in June: the 27th in 1966 (101) 100 degree days before 1900: Sept 7, 1881 (101) and July 31, 1898 (100) All 100 Degree Days Year Date / Temperature (°F) 2012 Jul 18/ 100 2011 Jul 22/ 104 Jul 23/ 100 2010 Jul 6/ 103 Jul 7/ 100 2001 Aug 9/ 103 1999 July 5/ 101 July 6th / 101 1995 July 15/ 102 1993 July 8/ 100 July 9/ 101 July 10/ 102 1991 July 20/ 100 July 21/ 102 1980 July 20/ 101 July 21/ 102 1977 July 18/ 100 July 19/ 102 July 21/ 104 1966 June 27/ 101 July 2/ 100 July 3/ 103 July 13/ 101 1957 July 21/ 100 July 22/ 101 1955 July 22/ 100 Aug 2/ 100 Aug 5/ 100 1954 July 14/ 100 July 31/ 100 1953 July 17/ 100 July 18/ 101 Aug 31/ 100 Sep/ 102 1952 June 26/ 100 1949 July 4/ 102 Aug 9/ 100 1948 Aug 26/ 103 Aug 27/ 101 Aug 28/ 100 1944 Aug 4/ 100 Aug 5/ 101 Aug 11/ 102 1937 July 9/ 100 July 10/ 100 1936 July 9/ 106 July 10/ 102 1934 June 29/ 101 1933 July 31/ 102 Aug/ 100 1930 July 21/ 102 1926 July 21/ 100 July 22/ 100 1918 Aug 7/ 104 1917 July 31/ 100 1911 July 3/ 100 1901 July 1/ 100 July 2/ 100 1898 July 3/ 100 1881 Sept 7/ 101

during the early 90s when we hadn't had any big snow seasons for over a decade, I used to go to the library and read NYT on microfiche and seasons of yore like 1947-48 and 1960-61 and 1966-67 and 1977-78

For NYC too, check out this old NYT article https://www.nytimes.com/1993/07/11/nyregion/heat-wave-records-rewritten-as-east-bakes-and-midwest-soaks.html

Were the total number of 100+ days (9) far in excess though? A few of them must have been in June and August in 1993.

Yes actually in some places it lowers the chances of big heat since it affects mins much more than it affects maxes plus more rainfall makes it much harder to have record heat in the summer here.

I just learned that the latest it ever hit 100 in NYC was on September 7th at 101, it was also the earliest it ever hit 100 in NYC because it happened in 1881 lol. We all believe in climate change but it doesn't affect every location in the same way and not all times of the year are affected in the same way either and it affects maxes and mins differently too. It's a much more complex issue than a +1.5 C rise across the board.

I was alive when this historic heatwave happened and I remember Craig Allen said it was 5.... was 7-11-1993 adjusted downward to 99? Back then Craig Allen said the high was 102 on that date, while it was 97 at NYC. The weird thing is I remember the total number of 100+ days as 9 so if one was taken away, another one must have been added later that summer to make the total unchanged. At any rate the magnitude of the heat in July 1993 was much higher than it was in 2022, most of those days barely touched 100.

-4 1993-07-07 through 1993-07-10 This can't be right, there were 5 consecutive days of 100+ at Newark in July 1993, and 3 consecutive days of 100+ at NYC and 2 consecutive days of 100+ at JFK (which is why the heat was of far greater magnitude than anything we have had since then. These three were our most historic heatwaves: 4 2010-07-04 through 2010-07-07 - 4 1993-07-07 through 1993-07-10 - 4 1953-08-28 through 1953-08-31 3 3 2011-07-21 through 2011-07-23

The all-time record for any month was 5 days in a row in July 2022. No Chris, it was in July 1993 when it was hot enough for the entire metro area to be above 100 and Newark had 5 days of 100+ in a row and 9 total.

hopefully the sea breeze is out by the hamptons where it belongs

Yes, I put it on the north side to keep it as far away from sunlight as possible, but it still recorded 93.7 last Thursday so I used the average of all four sensors (90.0 to 93.7) and came up with a high of 92 for that day.

Yes, and I've noticed it's a cascading effect because besides CO2 we also have more methane and more water vapor (all three are greenhouse gasses), we are becoming cloudier by the year which is increasing the impact, just like it did with Venus (even though its clouds have a different composition, mostly sulfuric acid.)

we need to look at some of these other sensors to see if they have any exposure to the sun and are properly sited too.

Humans have now reached the point where it's a runaway greenhouse effect. I remember there was an article posted that we are on the pathway to a similar fate as what happened to Venus.

Nice, I think we started exceeding that in the 1990s. I remember at the time that 1990 and 1991 were the two hottest years on record (both locally with 23 of 24 months above normal at NYC and globally with the hottest years on record up to that point.) If I remember what I read back then correctly, we jumped to a global mean temperature in the 57 degree range.

Yes, we've passed the point of benefits, which I believe ended in the 1990s. But the ice ages and the cold we had in the 1800s wasn't the ideal climate for humans either.