This value, reported as +0.30 deg. C above the 1991-2020 baseline, indicates a notable cooling from recent months in 2025. For context:
- November 2025: +0.43°C
- October 2025: +0.53°C
- September 2025: +0.53°C
This drop aligns with the ongoing La Niña conditions (which began influencing global temperatures with a lag) and the fading effects of the 2022 Hunga Tonga-Hunga Ha’apai eruption’s stratospheric water vapor injection, which had temporarily boosted anomalies in prior years.
This monthly update from Dr. Roy Spencer and John Christy at the University of Alabama in Huntsville is typically released early in the following month (e.g., around January 3-5, 2026). If this is the official release, it suggests continued cooling into early 2026, potentially making 2025 one of the warmer years on record but below the peaks of 2023-2024.
January 5th, 2026 by Roy W. Spencer, Ph. D.
2025 was the 2nd warmest year (a distant 2nd behind 2024) in the 47-year satellite record
The Version 6.1 global average lower tropospheric temperature (LT) anomaly for December 2025 was +0.30 deg. C departure from the 1991-2020 mean, down from the November 2025 value of +0.43 deg. C. (In the following plot note that the 13-month centered-average trace [red curve] has now been updated after several months of not being updated).
The Version 6.1 global area-averaged linear temperature trend (January 1979 through December 2025) remains at +0.16 deg/ C/decade (+0.22 C/decade over land, +0.13 C/decade over oceans).
2025 Ended the Year as a Distant 2nd Warmest Behind 2024
The following plot shows the ranking of the 47 years in the UAH satellite temperature record, from the warmest year (2024) to the coolest (1985). As can be seen, 2024 really was an anomalously warm year, more than can be attributed to El Nino alone.
The next plot shows how our UAH LT yearly anomalies compare to those posted on the WeatherBell website (subscription required) for the surface air temperatures from NOAA’s Climate Data Assimilation System (CDAS). There is pretty good correspondence between the two datasets, with LT having warm outliers during major El Ninos (especially 1987, 1998, 2010, and 2024). This behavior is due to extra heating of the troposphere (which LT measures) during El Nino by enhanced deep moist convection in the tropics when the tropical Pacific Ocean surface warms from reduced upwelling of cold water from below, an effect exaggerated by the several-month lag of tropospheric warming behind surface warming during El Nino:
The following table lists various regional Version 6.1 LT departures from the 30-year (1991-2020) average for the last 24 months (record highs are in red).
| YEAR | MO | GLOBE | NHEM. | SHEM. | TROPIC | USA48 | ARCTIC | AUST |
| 2024 | Jan | +0.80 | +1.02 | +0.57 | +1.20 | -0.19 | +0.40 | +1.12 |
| 2024 | Feb | +0.88 | +0.94 | +0.81 | +1.16 | +1.31 | +0.85 | +1.16 |
| 2024 | Mar | +0.88 | +0.96 | +0.80 | +1.25 | +0.22 | +1.05 | +1.34 |
| 2024 | Apr | +0.94 | +1.12 | +0.76 | +1.15 | +0.86 | +0.88 | +0.54 |
| 2024 | May | +0.77 | +0.77 | +0.78 | +1.20 | +0.04 | +0.20 | +0.52 |
| 2024 | June | +0.69 | +0.78 | +0.60 | +0.85 | +1.36 | +0.63 | +0.91 |
| 2024 | July | +0.73 | +0.86 | +0.61 | +0.96 | +0.44 | +0.56 | -0.07 |
| 2024 | Aug | +0.75 | +0.81 | +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 | +1.89 | +0.81 | +1.09 |
| 2024 | Nov | +0.64 | +0.87 | +0.40 | +0.53 | +1.11 | +0.79 | +1.00 |
| 2024 | Dec | +0.61 | +0.75 | +0.47 | +0.52 | +1.41 | +1.12 | +1.54 |
| 2025 | Jan | +0.45 | +0.70 | +0.21 | +0.24 | -1.07 | +0.74 | +0.48 |
| 2025 | Feb | +0.50 | +0.55 | +0.45 | +0.26 | +1.03 | +2.10 | +0.87 |
| 2025 | Mar | +0.57 | +0.73 | +0.41 | +0.40 | +1.24 | +1.23 | +1.20 |
| 2025 | Apr | +0.61 | +0.76 | +0.46 | +0.36 | +0.81 | +0.85 | +1.21 |
| 2025 | May | +0.50 | +0.45 | +0.55 | +0.30 | +0.15 | +0.75 | +0.98 |
| 2025 | June | +0.48 | +0.48 | +0.47 | +0.30 | +0.80 | +0.05 | +0.39 |
| 2025 | July | +0.36 | +0.49 | +0.23 | +0.45 | +0.32 | +0.40 | +0.53 |
| 2025 | Aug | +0.39 | +0.39 | +0.39 | +0.16 | -0.06 | +0.82 | +0.11 |
| 2025 | Sep | +0.53 | +0.56 | +0.49 | +0.35 | +0.38 | +0.77 | +0.30 |
| 2025 | Oct | +0.53 | +0.52 | +0.55 | +0.24 | +1.12 | +1.42 | +1.67 |
| 2025 | Nov | +0.43 | +0.59 | +0.27 | +0.24 | +1.32 | +0.78 | +0.36 |
| 2026 | Dec | +0.30 | +0.45 | +0.15 | +0.19 | +2.10 | +0.32 | +0.38 |
The full UAH Global Temperature Report, along with the LT global gridpoint anomaly map for December, 2025 as well as a global map of the 2025 anomalies, as well as 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:
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