Monthly climate report
Climate report: December 2025
Global land temperature (NASA GISTEMP v4) and atmospheric CO₂: where things stand at the end of December 2025.
Global temperature in December 2025
- December 2025 (land)
- +1.93 °Cversus 1901–1930
- Rank of the month
- 5thof 146 Decembers on record
- Year 2025
- +1.99 °C2nd of 146 years
- 12-month average
- +1.99 °C12 months ending December 2025
In December 2025, land areas worldwide were +1.93 °C warmer than the 1901–1930 average, according to NASA's GISTEMP v4 analysis, compared with +2.38 °C in December 2024. That makes it the 5th warmest December in 146 years of records. The record for this month remains December 2024 (+2.38 °C).
Over the whole of 2025, the average is +1.99 °C — the 2nd warmest year since 1880.
Over the 12 months ending in December 2025, the land average is +1.99 °C, against +2.15 °C over the previous 12 months. The highest 12-month average remains the one ending in August 2024 (+2.21 °C).
These figures cover land areas only. Land warms faster than the ocean, so the values are higher than the combined land-and-ocean averages usually quoted.
The last 13 months
| Month | Anomaly vs 1901–1930 |
|---|---|
| December 2025 | +1.93 °C |
| November 2025 | +2.01 °C |
| October 2025 | +1.85 °C |
| September 2025 | +2.05 °C |
| August 2025 | +1.78 °C |
| July 2025 | +1.44 °C |
| June 2025 | +1.69 °C |
| May 2025 | +1.70 °C |
| April 2025 | +2.23 °C |
| March 2025 | +2.53 °C |
| February 2025 | +2.07 °C |
| January 2025 | +2.56 °C |
| December 2024 | +2.38 °C |
The 10 warmest Decembers on record
Land areas, 1880–2025.
| # | Year | Anomaly vs 1901–1930 |
|---|---|---|
| 1 | December 2024 | +2.38 °C |
| 2 | December 2023 | +2.36 °C |
| 3 | December 2015 | +2.34 °C |
| 4 | December 2019 | +2.22 °C |
| 5 | December 2025this report | +1.93 °C |
| 6 | December 2017 | +1.90 °C |
| 7 | December 2021 | +1.85 °C |
| 8 | December 2003 | +1.83 °C |
| 9 | December 2006 | +1.77 °C |
| 10 | December 2016 | +1.67 °C |
Atmospheric CO₂
The annual mean rose from 421.08 ppm in 2023 to 424.60 ppm in 2024, +3.5 ppm in one year.
Sources and method
- Temperatures: NASA GISS, GISTEMP v4, monthly mean over land areas, rebased to 1901–1930 (file of November 14, 2026).
- Ranks use the months known at the date of the report. NASA slightly revises past values at each update, so figures can move by a few hundredths of a degree.
- CO₂: NOAA Global Monitoring Laboratory, Mauna Loa Observatory.