Published by Copernicus Climate Change Service

•    2023 is confirmed as the warmest calendar year in global temperature data records going back to 1850
•    2023 had a global-average temperature of 14.98°C, 0.17°C higher than the previous highest annual value in 2016
•    2023 was 0.60°C warmer than the 1991-2020 average and 1.48°C warmer than the 1850-1900 pre-industrial level
•    It is likely that a 12-month period ending in January or February 2024 will exceed 1.5°C above the pre-industrial level
•    Each month from June to December in 2023 was warmer than the corresponding month in any previous year
•    July and August 2023 were the warmest two months on record. Boreal summer (June-August) was also the warmest season on record 
•    In September 2023, the temperature deviation above the 1991–2020 average was larger than in any month in any year in the ERA5 dataset (0.93°C higher than the 1991-2020 average)
•    October, November and December 2023, each with a temperature of 0.85°C above average, ranked all joint second-largest in terms of temperature deviation above the 1991–2020 average