I make December 2024, using ERA5ERA ERA stands for 'ECMWF Re-Analysis' and refers to a series of research projects at ECMWF which produced various datasets (ERA-Interim, ERA-40, etcetera). daily global temperature data, the second warmest globally in the series that starts in 1940. Mean anomalies were just under 1.7°C degrees above the pre-industrial LTALTA Long Term Average. This is usually defined as a 30 year period by the WMO., and close to 0.1°C lower than they were in December 2023.