Record-breaking High-temperature Outlook for 2023: An Assessment Based on the China Global Merged Temperature (CMST) Dataset

According to the latest version (version 2.0) of the China global Merged Surface Temperature (CMST2.0) dataset, the global mean surface temperature (GMST) in the first half of 2023 reached its third warmest value since the period of instrumental observation began, being only slightly lower than the values recorded in 2016 and 2020, and historically record-breaking GMST emerged from May to July 2023. Further analysis also indicates that if the surface temperature in the last five months of 2023 approaches the average level of the past five years, the annual average surface temperature anomaly in 2023 of approximately 1.26°C will break the previous highest surface temperature, which was recorded in 2016 of approximately 1.25°C (both values relative to the global pre-industrialization period, i.e., the average value from 1850 to 1900). With El Niño triggering a record-breaking hottest July, record-breaking average annual temperatures will most likely become a reality in 2023.