UAH Global Temperature Update for September, 2024: +0.96 deg. C

October 2nd, 2024 by Roy W. Spencer, Ph. D.

The Version 6 global average lower tropospheric temperature (LT) anomaly for September, 2024 was +0.96 deg. C departure from the 1991-2020 mean, up from the August, 2024 anomaly of +0.88 deg. C.

The linear warming trend since January, 1979 remains at +0.16 C/decade (+0.14 C/decade over the global-averaged oceans, and +0.21 C/decade over global-averaged land).

The following table lists various regional LT departures from the 30-year (1991-2020) average for the last 21 months (record highs are in red):

YEARMOGLOBENHEM.SHEM.TROPICUSA48ARCTICAUST
2023Jan-0.04+0.05-0.13-0.38+0.12-0.12-0.50
2023Feb+0.09+0.17+0.00-0.10+0.68-0.24-0.11
2023Mar+0.20+0.24+0.17-0.13-1.43+0.17+0.40
2023Apr+0.18+0.11+0.26-0.03-0.37+0.53+0.21
2023May+0.37+0.30+0.44+0.40+0.57+0.66-0.09
2023June+0.38+0.47+0.29+0.55-0.35+0.45+0.07
2023July+0.64+0.73+0.56+0.88+0.53+0.91+1.44
2023Aug+0.70+0.88+0.51+0.86+0.94+1.54+1.25
2023Sep+0.90+0.94+0.86+0.93+0.40+1.13+1.17
2023Oct+0.93+1.02+0.83+1.00+0.99+0.92+0.63
2023Nov+0.91+1.01+0.82+1.03+0.65+1.16+0.42
2023Dec+0.83+0.93+0.73+1.08+1.26+0.26+0.85
2024Jan+0.86+1.06+0.66+1.27-0.05+0.40+1.18
2024Feb+0.93+1.03+0.83+1.24+1.36+0.88+1.07
2024Mar+0.95+1.02+0.88+1.35+0.23+1.10+1.29
2024Apr+1.05+1.25+0.85+1.26+1.02+0.98+0.48
2024May+0.90+0.98+0.83+1.31+0.38+0.38+0.45
2024June+0.80+0.96+0.64+0.93+1.65+0.79+0.87
2024July+0.85+1.02+0.68+1.06+0.77+0.67+0.01
2024Aug+0.88+0.96+0.81+0.88+0.69+0.94+1.80
2024Sep+0.96+1.21+0.71+0.97+1.56+1.54+1.16

The full UAH Global Temperature Report, along with the LT global gridpoint anomaly image for September, 2024, and a more detailed analysis by John Christy, should be available within the next several days here.

Lower Troposphere:

http://vortex.nsstc.uah.edu/data/msu/v6.0/tlt/uahncdc_lt_6.0.txt

Mid-Troposphere:

http://vortex.nsstc.uah.edu/data/msu/v6.0/tmt/uahncdc_mt_6.0.txt

Tropopause:

http://vortex.nsstc.uah.edu/data/msu/v6.0/ttp/uahncdc_tp_6.0.txt

Lower Stratosphere:

http://vortex.nsstc.uah.edu/data/msu/v6.0/tls/uahncdc_ls_6.0.txt


78 Responses to “UAH Global Temperature Update for September, 2024: +0.96 deg. C”

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  1. skeptikal says:

    Roy, this is clearly a step-up that has to be questioned. Have you found any reason that this could occur?

    • barry says:

      If we ever find out I’m pretty sure it will be a combination of factors, rather than one geological finger on the scale.

    • Clint R says:

      September was a battle between the developing La Niña and the residual HTE.

      The HTE will continue to dissipate. So as La Niña fully forms temperatures should drop.

    • Mark B says:

      I disagree that this is “clearly a step-up that has to be questioned” in that it is reasonably within the month to month variability typical of this dataset. The expectation certainly is that UAH anomalies will tend downward with the probable La Nina in the coming months, but it’s too early to declare another month at or near the peak from the recent El Nino as a wild outlier.

      There has been some discussion of the peak being attributed to contributions from El Nino, Hunga Tonga, and the marine sulphur emissions reductions, but the mainstream consensus seems to be that the effect or forcing from these factors combined aren’t sufficient to explain the magnitude of the recent peak. It could be that the sensitivity to the one or both of the latter two is greatly underestimated, but implicitly arguing for greater sensitivity would ought to be uncomfortable for mitigation skeptics hoping to maintain some level of self-consistency.

    • Nate says:

      Aside from the reduction in marine aerosol (sulfur) emissions, there has been a considerable reduction in aerosol pollution from Asia over the last decade or so. This is believed to have reduced the cooling effect of aerosols that has been partially cancelling the GHG warming.

      This may be partly responsible for the persistent warm anomaly in the North Pacific.

      https://www.science.org/content/article/deadly-pacific-blobs-tied-emission-cuts-china

      Together with the quite warm N. Atlantic, the overall global sea surface temperature has continued its streak of record warmth.

      https://climatereanalyzer.org/clim/sst_daily/?dm_id=world2

  2. TheFinalNail says:

    That’s the 15th straight new record warmest monthly temperature. Every month since July 2023 has set a new monthly temperature record. What on earth is going on? The 2023/24 El Nino ended in May.

    I think the anomaly for the 3 remaining months in 2024 would have to average around -0.7C in order for 2024 not to surpass 2023 as the warmest year on record for UAH. Can’t see that happening.

  3. Bellman says:

    That’s really surprising. I was expecting this month to be cooler that last September.

    This makes 15 months in a row to set a monthly record. The ten warmest Septembers are now:

    1 2024 0.96
    2 2023 0.90
    3 2019 0.46
    4 2020 0.41
    5 2017 0.40
    6 2016 0.30
    7 1998 0.27
    8 2021 0.27
    9 2022 0.25
    10 2010 0.19

    Interesting to see how much cooler the previous El Nino Septembers of 1998 and 2016 were.

  4. Bellman says:

    My simplistic projection for 2024 is now 0.85 +/- 0.08. It’s difficult at this stage to see 2024 as not beating the 2023 record, the question is by how much. At present it look like beating the record by at least 0.25C.

  5. Antonin Qwerty says:

    September was the first month there was a noticeable drop after the 1998 El Nino. The big drop came in November.

    But then, in September 1998 we were already well into La Nina, and approaching a strong one, with ENSO3.4 already down to -1.3. This September it will probably only be around -0.4.

    (Someone here will now present the deprecated ENSO3.4 data graph instead of the official data, and without providing the 1998 data from that source for comparison.)

  6. Bellman says:

    This is also the warmest USA September, just beating September 1998 at 1.50C. And the warmest Arctic September, beating last years 1.14C by some margin. Australia was 0.01C cooler than last year’s record September.

    It’s also a record September for the Northern Hemisphere, beating last year’s record by 0.27C.

  7. bdgwx says:

    Here is the Monckton Pause update for September. At its peak it lasted 107 months starting in 2014/06. Since 2014/06 the warming trend is now +0.42 C/decade.

    Here are some more trends

    1st half: +0.14 C.decade-1
    2nd half: +0.23 C.decade-1

    Last 10 years: +0.41 C.decade-1
    Last 15 years: +0.39 C.decade-1
    Last 20 years: +0.30 C.decade-1
    Last 25 years: +0.23 C.decade-1
    Last 30 years: +0.17 C.decade-1

    The acceleration is now at +0.03 C.decade-2.

    • Antonin Qwerty says:

      I’m afraid I’m going to have to cross the floor on this one and point out how meaningless a 10-year trend is in terms of having a predictive value.

      • bdgwx says:

        I don’t disagree but Monckton made a big stink about how the warming had paused (and interpreted by many as an outright stoppage) by considering only the last <9 years in his monthly updates. I'm pointing out that since the start of his cherry picked pause the warming rate is now even higher than that of the overall trend.

        It is also interesting to note that the warming trend up to 2014/06 (the start of his pause) was only +0.11 C.decade-1. And if we include the 107 months of the pause it is actually +0.14 C.decade-1. So his pause actually increased the overall warming rate. Simpson's Paradox.

      • Antonin Qwerty says:

        If the point is to shine light on Monckton’s lunacy then it is a point well made. Unfortunately this new peak will only serve to reset the baseline for a new instalment of his nonsense.

      • John W says:

        WUWT lost its credibility long ago when they discredited Berkeley Earth after it reported results consistent with other surface datasets. If I remember correctly, Watts said he would accept the result no matter.

      • bdgwx says:

        You remember correctly. He said “I’m prepared to accept whatever result they produce, even if it proves my premise wrong” They is Berkeley Earth.

    • barry says:

      I’m sure predictive value was not bdgwx’s point.

    • Bill hunter says:

      bdgwx says: ”The acceleration is now at +0.03 C.decade-2.”

      Natural climate change via orbital forcing at its finest. It was bound to reveal itself on the solar system scale of time and here it is folks! this is not CO2 its not ENSO, in fact it seems to have been killing ENSO seasonal forecasts dating back to January.

      time to wake up and address natural climate change via orbital forcing! there hasn’t been a big poof of CO2 that could account for it but there clearly is a planetary alignment.

      • nate says:

        “Natural climate change via orbital forcing at its finest.”

        Fantasy that cannot be supported with actual science. Oh well..

      • Bill hunter says:

        What science is available on the matter says otherwise Nate. Orbital forcing is real and is taught at a high level in the universities. What they don’t look at because of corruption is the eccentricity clock has much more than one hand on it.

      • AverageJon says:

        I think that everybody here will agree that orbital forcing exists. The question is: what makes you so sure that the warming we’ve seen recently has been caused by orbital forcing?
        Can you point us to any research from a few years ago that predicted orbital forcing to cause this amount of warming?

      • Nate says:

        Nah,you have not made a convincing science based argument. Until you do, this is Astrology.

    • RLH says:

      Are you suggesting that the acceleration is caused by CO2 increasing?

    • Bad Andrew says:

      “Im prepared to accept whatever result they produce”

      Wow. That’s a naive thing to say.

      Andrew

    • Bindidon says:

      ” time to wake up and address natural climate change via orbital forcing! ”

      Apparently, the Hunter boy has discovered his newest toy: orbital forcing is now the major aspect driving climate, if not even the only one.

      Sources, Hunter boy?

  8. barry says:

    September was also the 2nd highest anomaly in the entire dataset, beaten by April at 1.05 C.

    Truly a remarkable couple of years in the record. I’d question the instruments or processing of the data, but GSAT corroborates (it will be interesting to see the September anomalies for the surface datasets). This is a ‘Tenberth’ moment, where we can’t yet account for the distribution of energy to make sense of this.

    • Clint R says:

      barry, are you pretending you never heard of the HTE?

      • Dixon says:

        I was pinning the step up on HTE. But why the lag?

        Are we puzzling over the lack of a step down from a mighty step up, when we should be wondering why 2020 to 2023 was so cool? Global airline traffic plummeted during that time. Perhaps contrails cause warming…

      • luke says:

        What is HTE?

      • Clint R says:

        luke, HTE is the “Hunga-Tonga Effect”. It was caused by the huge underwater volcano that launched millions of gallons of water into the Stratosphere. The combined effect includes atmospheric waves that disrupted the Polar Vortex, a REAL greenhouse effect from the water vapor, and possible yet-to-be determined effects from the chemistry of chlorine and ozone.

        The atmospheric waves have subsided, but the water vapor has been slow to leave the Stratosphere.

        Such a massive underwater eruption has not been observed in modern satellite times, so it’s a learning experience.

      • Bindidon says:

        Interestingly, when he talks about Hunga Tonga, GHE and global warming denier Clint R always hides the fact that not only 150 Gt water were ‘launched’ up to the stratosphere (everybody now knows this), but also a more decent though substantial amount of sulfur dioxide.

        Who wants to get more info about the HTE looks best at the sources linked to in the document

        Hunga Tonga-Hunga Ha’apai Volcano Eruption Research

        2022 – 2025

        https://csl.noaa.gov/news/topics/hthh.html

    • Ken says:

      The only consequence of a ‘Tenberth’ moment is that you will be able to successfully and consistently grow crops 1 degree latitude further North.

      ‘Climate crisis’ is not evident in any salient data.

      • Nate says:

        Oh, and more extremely damaging events like Helene.

      • Arkady Ivanovich says:

        And Rising Tree Cover Loss Amid Increasing Forest Fires: https://ibb.co/JqBD6HG

      • Ken says:

        There is no way to attribute Helene to climate crisis narrative.

      • Ken says:

        There is no trend in fire data. The paleological data suggests that there have always been more fires than there are now as a result of fire suppression efforts.

      • Arkady Ivanovich says:

        Yes there is a trend.

      • Arkady Ivanovich says:

        Data on forest fires reveals that they now consume at least twice as much tree cover as they did 23 years ago. In this context, “loss due to fires” refers to the direct loss of tree canopy cover caused by both natural and human-ignited fires.

        Fire is also making up a larger share of global tree cover loss compared to other drivers like mining and forestry. Fires only accounted for about 20% of all tree cover loss in 2001, they now account for roughly 33%.

        https://ibb.co/JqBD6HG

      • Arkady Ivanovich says:

        Climate change is a key factor driving the increase in fire activity, as rising temperatures dry out landscapes, creating conditions that are more favorable for larger and more frequent forest fires.

      • Arkady Ivanovich says:

        I think your brain is Heavily Saturated with bad information.

      • Ken says:

        “Climate change is a key factor driving the increase in fire activity, as rising temperatures dry out landscapes, creating conditions that are more favorable for larger and more frequent forest fires.”

        The problem of human interference with the forest cycle is a much larger factor. We’ve been attacking forest fires with water bombers for a hundred years with the net result that there is a lot of fuel on the forest floor. Now if a fire gets started its almost impossible to put out.

      • Ken says:

        Here is Jasper Fire critique of bad forest managem ent being responsible.

        https://www.youtube.com/watch?v=4l7RXI3o9eg

      • Nate says:

        “There is no way to attribute Helene to climate crisis narrative.”

        Yes there is. Meteorologists agree that the unusually warm T of the ocean in the path of the hurricane can result in rapid intensification and greater rainfall amounts.

        The ocean has warmed due to GW.

      • Ken says:

        You’d have to show there is a trend of more frequent more severe hurricanes. A one of severe weather event like Helene isn’t an indicator of climate change.

        Recall Helene was a Cat 4; not a hurricane that is unprecedented on the scale.

        Yeah, I feel for the people who got impacted from the record rains and the ensuing flooding, but its not climate change; its just weather.

  9. Nate says:

    The global sea surface temperature is back to breaking records, even with the cooler central Pacific. Suggests we have may entered a new normal of elevated ocean temps.

    https://climatereanalyzer.org/clim/sst_daily/?dm_id=world2

    Tellingly, they haven’t been updated for a week because the data center is in Asheville, NC, destroyed by Hurricane Helene.

  10. Luke says:

    WHAT IS THE MONCTON PAUSE?

    • bdgwx says:

      Christopher Monckton of Brenchley devised a procedure in which an ordinary least squares regression is performed on monthly UAH TLT values such that there is one linear trend value calculated per month which includes all of the completed months occurring after it. You then find the first occurrence (by month and year) of a zero or negative value. That marks the start of the so called Monckton Pause.

      https://tinyurl.com/monckton107

      • Bindidon says:

        Things have been very quiet around the third Viscount of Brenchley’s pause for at least a year now…

      • Richard Barraclough says:

        Yes, indeed.

        This could be the longest pause ever recorded in the appearance of Monkton’s articles

  11. Bad Andrew says:

    Skewed. Broke. No Explanation.

    Andrew

    • John W says:

      You’ve mentioned this every month but haven’t provided any evidence to support your claims. How do you account for the corroboration of this anomaly with the surface datasets?

      • Bad Andrew says:

        John,

        The evidence is the graph itself. The implication is that whatever is being represented no longer operates the way it has. And because there is no explanation for the skew, and because it’s a highly contrived presentation to begin with, the logical conclusion is that we don’t know that the graph is meaningful.

        Corroboration is irrelevant.

        Andrew

      • Willard says:

        Skewed. Broke. No Explanation.

        The evidence is in Andrew’s comments themselves.

        Willard

  12. Bindidon says:

    skeptikal

    You wrote:

    ” Roy, this is clearly a step-up that has to be questioned. Have you found any reason that this could occur? ”

    It’s interesting to see how the lower troposphere (UAH 6.0 , NOAA STAR and RSS 4.0) behave compared to the surface (GISS V4 and Had~CRUT 5) since Jan 2020:

    https://drive.google.com/file/d/1s2N27WGL5N5hJejXO_ZtCiSdbRWVSkxh/view

    (Had~CRUT 5 till July, RSS and STAR till August 2024)

    *
    Why should UAH’s step-up be questioned, when even the surface has shown in 2023 departures quite similar to those of the troposphere?

  13. RLH says:

    Are Hurricanes Getting Stronger?

    “Hurricane Helene has brought out the usual claims that global warming is making hurricanes more powerful, a belief fed by disinformation in the media.

    I have even seen a remarkably silly comment by somebody today that they when they look at report of Helene, they can see climate change happening.

    Two simple pieces of fact show this to be nonsense.”

    https://wattsupwiththat.com/2024/09/30/are-hurricanes-getting-stronger/

  14. Bad Andrew says:

    “Why should UAHs step-up be questioned”

    The why has already been provided. You just pretend you didn’t read it.

    Andrew

    • bdgwx says:

      As best I can tell your argument is supported solely by the result shown by UAH; not by any specific deficiency you feel exists as part of producing that result. That is what I like to call a “nuh-uh” argument or argument by incredulity. Arguments of this form do not resonate well with us curmudgeonly skeptics.

      They way you capture the attention of us curmudgeonly skeptics is to clearly explain the deficiency in the methodology, how it caused the wrong result, how to get the right result, and what the right result actually is so that we can compare and contrast the two approaches.

      As it is right now we tend to follow Hitchen’s Razor. We can be asserted without evidence can also be dismissed without evidence.

  15. Willard says:

    SOLAR MINIMUM UPDATE

    In the case of Helene, climate change caused it to drop 50 per cent more rainfall in some parts of Georgia and the Carolinas, and made those record rainfalls up to 20 times more likely, reported researchers at Lawrence Berkeley National Laboratory in a rapid climate attribution study released Monday. That study is based on methods used for a similar study on Hurricane Harvey, but has not yet been peer reviewed.

    https://www.cbc.ca/news/science/hurricane-helene-science-1.7339012

    Provisional analysis beats incredulity.

    • Ken says:

      Youd have to show there is a trend of more frequent more severe hurricanes. A one-of severe weather event like Helene isnt an indicator of climate change.

      Recall Helene was a Cat 4; not a hurricane that is unprecedented on the scale.

      Yeah, I feel for the people who got impacted from the record rains and the ensuing flooding, but its not climate change; its just weather.

    • Ken says:

      CBC isn’t a source of credible information; its yellow journalism.

  16. Eben says:

    The sudden step up like this cannot be real , somebody has altered something
    Consider this data set to be toast

    • Entropic man says:

      Somebody has altered something.

      None of the natural processes being monitored, even the HTE, have changed enough to produce this sudden step up.

      This is artificial.

    • Bad Andrew says:

      “Consider this data set to be toast”

      Make it wheat with a “healthy” smear of butter.

      Andrew

  17. Sren F says:

    Seems to me for each month this level warmth just continue, and in particular if doing so despite a solid La Nina ahead, and with the full-planet stratospheric water only very slowly residing, it’d dawn on all that it can only be the unique 200-year-or-so-recurrence HTE event behind.

    • RLH says:

      Well it can’t be down to the increase in the same time in CO2.

    • bdgwx says:

      Do you have a hypothesis that can explain how only 150 MtH2O was able to yield this much warming?

      Do you have a hypothesis that can explain how the nearly 10,000 MtCO2 that accumulated in the stratosphere after the HT eruption was unable to have the same or higher magnitude of effect as the 150 MtH20?

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