Home/BlogThe Version 6.1 global average lower tropospheric temperature (LT) anomaly for May, 2025 was +0.50 deg. C departure from the 1991-2020 mean, down from the April, 2025 anomaly of +0.61 deg. C.
The Version 6.1 global area-averaged linear temperature trend (January 1979 through May 2025) remains at +0.15 deg/ C/decade (+0.22 C/decade over land, +0.13 C/decade over oceans).
The following table lists various regional Version 6.1 LT departures from the 30-year (1991-2020) average for the last 17 months (record highs are in red).
| YEAR | MO | GLOBE | NHEM. | SHEM. | TROPIC | USA48 | ARCTIC | AUST |
| 2024 | Jan | +0.80 | +1.02 | +0.58 | +1.20 | -0.19 | +0.40 | +1.12 |
| 2024 | Feb | +0.88 | +0.95 | +0.81 | +1.17 | +1.31 | +0.86 | +1.16 |
| 2024 | Mar | +0.88 | +0.96 | +0.80 | +1.26 | +0.22 | +1.05 | +1.34 |
| 2024 | Apr | +0.94 | +1.12 | +0.76 | +1.15 | +0.86 | +0.88 | +0.54 |
| 2024 | May | +0.78 | +0.77 | +0.78 | +1.20 | +0.05 | +0.20 | +0.53 |
| 2024 | June | +0.69 | +0.78 | +0.60 | +0.85 | +1.37 | +0.64 | +0.91 |
| 2024 | July | +0.74 | +0.86 | +0.61 | +0.97 | +0.44 | +0.56 | -0.07 |
| 2024 | Aug | +0.76 | +0.82 | +0.69 | +0.74 | +0.40 | +0.88 | +1.75 |
| 2024 | Sep | +0.81 | +1.04 | +0.58 | +0.82 | +1.31 | +1.48 | +0.98 |
| 2024 | Oct | +0.75 | +0.89 | +0.60 | +0.63 | +1.90 | +0.81 | +1.09 |
| 2024 | Nov | +0.64 | +0.87 | +0.41 | +0.53 | +1.12 | +0.79 | +1.00 |
| 2024 | Dec | +0.62 | +0.76 | +0.48 | +0.52 | +1.42 | +1.12 | +1.54 |
| 2025 | Jan | +0.45 | +0.70 | +0.21 | +0.24 | -1.06 | +0.74 | +0.48 |
| 2025 | Feb | +0.50 | +0.55 | +0.45 | +0.26 | +1.04 | +2.10 | +0.87 |
| 2025 | Mar | +0.57 | +0.74 | +0.41 | +0.40 | +1.24 | +1.23 | +1.20 |
| 2025 | Apr | +0.61 | +0.77 | +0.46 | +0.37 | +0.82 | +0.85 | +1.21 |
| 2025 | May | +0.50 | +0.45 | +0.55 | +0.30 | +0.15 | +0.75 | +0.99 |
The full UAH Global Temperature Report, along with the LT global gridpoint anomaly image for May, 2025, and a more detailed analysis by John Christy, should be available within the next several days here.
The monthly anomalies for various regions for the four deep layers we monitor from satellites will be available in the next several days at the following locations:
Third warmest May since 1979, not quite beating the 1998 outlier.
Ten warmest Mays
Year Anomaly
1 2024 0.78
2 1998 0.52
3 2025 0.50
4 2016 0.42
5 2020 0.42
6 2017 0.32
7 2010 0.29
8 2023 0.28
9 2019 0.20
10 2015 0.14
My simplistic projection for 2025 creeps up another 0.01C. Now 0.49 +/- 0.13C. There is an 80% chance that 2025 will be warmer than 2023.
The trend is downward (and has been for a few months now).
Of course temperatures are coming down, that’s what happens when you have a record breaking spike. The question is how far and how quickly will it fall.
“The question is how far and how quickly will it fall.”
How far do you think the fall will be?
Waiting, waiting for a detailed, hard science explanation (with numbers analysed) of the mechanism for this several months of declining trend from those who still promote that CO2 is the control knob. Geoff S
Geoff Sherrington says:
Waiting, waiting for a detailed, hard science explanation (with numbers analysed) of the mechanism for this several months of declining trend from those who still promote that CO2 is the control knob.
Ending of the 2023-24 El Nino.
Yep. And it is quite a bit warmer than after the previous El Nino ended
To the cult, when temps go up it’s due to CO2. But when temps go down, it’s due to “natural variability”.
If they understood the physics, it’s ALL due to natural variability.
But of course, they don’t understand….
The CO2 “control knob” exerts its influence over decades, not months.
When oh when will people learn the difference between climate and weather?
https://oz4caster.wordpress.com/wp-content/uploads/2025/06/d4-gfs-gta-daily-2014-2025-06-04.gif
And others agree!
Yet predictable based on El Nino followed by La Nina/Neutral.
How far do you think the fall will be?
What El Nino/La Nina?
The signal to noise ratio decreased in July 2023, when the global temperature anomaly spiked abruptly and unusually. If that spike triggered cascading effects in other systems, such as the cryosphere or oceans, the SNR degrades even further over time.
It will likely take years, if not decades, of new observations to establish a reliable new baseline.
Bellman
People like RLH are always looking at tiny downward looking bits, but deliberately dissimulate the context around the bits.
Here is a chart showing the running trend in C / decade for UAH 6.1 LT, from the starting period
Dec 1978 – Dec 1999 (0.149 +- 0.02)
till that computed right now
Dec 1978 – May 2025 (0.155 +- 0.01)
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https://drive.google.com/file/d/1jXp9gn9SR4NvvzsSHwRXQyd_jbgVpX6b/view
There is currently NO downeard trend at all.
Oz4caster’s running trend will certainly be no different.
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And by the way: his chart starts with 2014; UAH’s LT trend for Jan 2014 till May 2025 is only… 0.384 +- 0.06 :-))
Moreover, nothing spiked unusually since 2023: you just need to lokk at UAH’s running trend and will see for example a similar trend increase between March 2001 and March 2003.
Amazingly, the trend difference for that period is (down to 5 digits atdp) even exactly identical to the difference between April 2023 and May 2025: 0.02396 C / decade.
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These spikes however can’t compete with the big drop the UAH LT time series experienced from March 2007 down to December 2009: -0.02786 C / decade.
Such differences look ridiculously small at a first glance; but please think that we look at a value range between 0.11 and 0.16.
Wrong!
You are focusing on a different metric, which overlooks some important aspects of the situation.
The satellite measurements lag SSTs by ~3-4 months, so a spike in satellite temperature in July 2023 reflects oceanic conditions from March-April 2023.
According to NOAA OIST data, global SSTs broke the super El Ni-ño 2016 record in early March 2023 and remained above it thereafter. This happened even while the climate system was officially still in La Ni-ña.
That is extremely difficult to explain using conventional natural variability alone.
Looks like we’re back to square one. Only 28 more years to go for a new reliable baseline for the WMO to use.
Finally, I saw that I forgot to add in the chart the period which had the greatest trend increase for the trend periods greater than about 15 years: that moving from UAH’s lowest trend (Dec 1978 – Apr 1994) after the Pinatubo eruption, up to the highest UAH trend (Dec 1978 – Feb 1999) following the 1997/98 El Nino.
This is the corrected running trend chart:
https://drive.google.com/file/d/1eSHRwujG1zkLBSMHYd79O3uS_Had0GmV/view
We can now see that the trend increase between post-Pinatubo and post-Nino 97/98 makes all subsequent drops and peaks seem secondary.
Data smoothing with 10 year averages does not illuminate the data trends, it hides it. Congratulations! Your graph is wrong anyway because you cannot have a 10-year trend in the current year. The last possible year is 2020.
Nice try, but a rather poor effort again.
Bindidon, trends are most sensitive to noise early in the dataset, so it is no surprise the 1998 El Ni-ño, which was exceptionally strong and occurred just as the trend turned positive, produced the largest spike in your trend based record.
Yet here you are criticizing RLH for pointing out a short term cooling period. At least he chose a window that begins after the signal to noise ratio shifted.
Now look at 2016: a comparable El Ni-ño, but far more muted in your trend plot because it landed over 20 years into a longer, more stable dataset.
Looks like the warmest autumn/fall on record for Australia. +1.13C on average for Mar-May. Beats the previous Oz autumn record in UAH, +0.88 in 2016, by +0.25C.
The Monckton Pause extends to 24 months starting in 2023/05. The average of this pause is 0.67 C. The previous Monckton Pause started in 2014/06 and lasted 107 months and had an average of 0.21 C. That makes this pause 0.46 C higher than the previous one.
My prediction for 2025 from the March update was 0.43 +/- 0.16 C.
My prediction for 2025 from the April update was 0.47 +/- 0.14 C.
My prediction for 2025 using the May update is now 0.46 +/- 0.11 C.
The last 20 y trend is 0.3 C/decade.
May 2025 ENSO update: eye of neutral
https://www.climate.gov/news-features/blogs/enso/may-2025-enso-update-eye-neutral
The atmosphere is cooling. Everything is consistent with an unexplained sharp rise that is now retreating. The volcano theory may be more than just hot air. The ship exhaust was already rather far-fetched, and mostly just a bunch of smoke from Hansen. ENSO does not seem to explain this either. The mystery continues. On to next month for more clues.
It is a mystery only if you believe the step up is real
Mid-Troposphere
https://www.nsstc.uah.edu/data/msu/v6.1/tmt/uahncdc_mt_6.1.txt
Since the 2016 revision to UAH that lowered the trend from the old 5.6 version, the long term trend has risen with nearly every new month’s data.
This is a record-breaking spike in tropospheric temperatures, initiated by a moderate El Niño event in the Pacific. The anomaly may have been amplified by the massive water vapor injection from the Tonga eruption. Other reason so large a spike?
Good point. We can’t forget the HTE. The water vapor is slowly dissipating:
https://postimg.cc/tnzppz8y