Home/BlogThe Version 6.1 global average lower tropospheric temperature (LT) anomaly for January, 2025 was +0.46 deg. C departure from the 1991-2020 mean, down substantially from the December, 2024 anomaly of +0.62 deg. Most of this cooling was over the global oceans.
The Version 6.1 global area-averaged temperature trend (January 1979 through January 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 13 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 | +0.77 | +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 | +0.70 | +0.75 | +0.41 | +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 | +0.61 | +0.64 | +1.90 | +0.81 | +1.09 |
| 2024 | Nov | +0.64 | +0.88 | +0.41 | +0.53 | +1.12 | +0.79 | +1.00 |
| 2024 | Dec | +0.62 | +0.76 | +0.48 | +0.53 | +1.42 | +1.12 | +1.54 |
| 2025 | Jan | +0.46 | +0.70 | +0.21 | +0.24 | -1.06 | +0.74 | +0.48 |
The full UAH Global Temperature Report, along with the LT global gridpoint anomaly image for January, 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:
Well, finally.
If it keeps dropping precipitously, it won’t look all that different to 98. If.
“If it keeps dropping precipitously, it wont look all that different to 98. ”
Except 1998 was a single year, where 2023 and 2024 were both record breaking.
Here’s what it looks like using a 24 month rolling average.
https://i.imgur.com/Ducv1ii.png
Here’s a direct comparison of the years from 1997 and 2023.
https://i.imgur.com/PEllNHw.png
The recent spike lasted much longer than in 1998.
That confirms what I perceived going by eye: This peak looks wider. I was actually starting to consider that it might be a step-change, and not go back down at all. But that would have been a real surprise. If the trend were so strong as to drown out periodic fluctuations we would be in real trouble. Fortunately there’s no indication of that.
Does anyone have a link to a graph of the lower stratosphere which is up to date? Thanks.
La Niña is here: https://www.climate.gov/news-features/blogs/enso/january-2025-update-la-nina-here
Interesting contrast to ERA which has this January warmer than last year.
UAH still makes this the 2nd warmest January. The ten warmest Januaries so far.
2024 0.80
2025 0.46
2016 0.42
2020 0.42
2010 0.36
1998 0.34
2013 0.31
2007 0.29
2017 0.26
2019 0.24
I wonder if the strong solar activity over the last two years could have something to do with it. Sure, the data do not indicate something unusual with the peak of cycle 25, but observations tell a different story.
Over the past two years again and again there were northern lights over Austria, and large parts of Europe over all. They almost became a common sight. The last time that happened was in the years 1938 to 1941, during cycle 17. Since then there was nothing.
Also interesting is the energy emitted by these mass ejections. Although it is hard to get any precise figures, using the few hints there are, they should not be negligible.
Slightly cooler than I expected with only a weak La Nina. Could be a sign the recovery from Hunga Tonga is accelerating. More likely, last month was just a slightly higher than is should have been.
If we assume a recovery from HTe of around 0.05 C / month, it’s going to take about 6-8 months to fully recover.
We still could see UAH continue to drop about 0.1 C / month through May but then flatten out as this La Nina, ends.
With this cooling on top of the Willis E article showing the CERES data (which verified Miskolczi 2010), there can be no doubt that AGW is fiction.
There is no ‘recovery’ from Hunga Tonga as it had no influence.
Something led to a large reduction in clouds which started the month after the eruption. In this case the correlation is solid.
The HadCRUT dataset has not yet been updated, but I expect a similar drop. This plot compares the current spike to the spike following the 1875 eruption of Askja — a wet volcano. I wouldn’t be so quick to dismiss HT.
https://localartist.org/media/HTvAkjsaENSO.png
You said it had no influence. I’ve read that it increased stratospheric humidity by as much as 10%. That would explain the temperature spike.
It was WAY cooler than I expected, Richard M.
I saw the battle between La Niña (cooling), weakened Polar Vortex (warming) and HTE (warming). Just looking at the charts, I expected the anomaly to be higher (warmer).
Maybe this means the HTE is, finally, no longer a factor?
Poor short term correlation with surface temps, which showed a rise this month.
Rise for January on surface.
https://oz4caster.wordpress.com/monthly-trends/
https://www.tandfonline.com/doi/full/10.1080/00139157.2025.2434494
Article finds recent T step-up is due to shipping aerosol reductions.
“This temperature jump was spurred by one of the periodic tropical El Nino warming events, but many Earth scientists were baffled by the magnitude of the global warming, which was twice as large as expected for the weak 2023-2024 El Nino. We find that most of the other half of the warming was caused by a restriction on aerosol emissions by ships, which was imposed in 2020 by the International Maritime Organization to combat the effect of aerosol pollutants on human health.”