January 2025 has been one of the warmest on record, accompanied by a reduction in ice cover as a consequence of the average increase in temperatures. The first month of 2025 was the warmest, continuing the series of record-breaking temperatures observed over the past two years. According to the January 2025 monthly bulletin from the Copernicus Climate Change Service (C3S), the global average surface temperature, based on the ERA5 reanalysis dataset, was 13.23°C, which is 0.79°C above the January climatological average for the 1991-2020 period. Additionally, the Arctic recorded the lowest sea ice extent ever observed in January.
Compared to the 1850-1900 average, which is designated as the pre-industrial reference period, January 2025 was 1.75°C warmer than the average for that month.
During this period, the Arctic saw the lowest sea ice extent for January, 6% below the 1991-2020 average.
Source: https://climate.copernicus.eu/january-2025-warmest-january-and-lowest-arctic-sea-ice-extent-month