CLIMATE CHALLENGESFirst Three Weeks of July 2023 Warmest on Record, Breaking Global Temperature Records

Published 27 July 2023

Following the hottest June on record and a series of extreme weather events, including heatwaves in Europe, North America and Asia, and wildfires in Canada and Greece, show that the first three weeks of July have already broken several significant records. The first three weeks of the month was the warmest three-week period on record.

Following the hottest June on record and a series of extreme weather events, including heatwaves in Europe, North America and Asia, and wildfires in Canada and Greece, ERA5 data from the Copernicus Climate Change Service (C3S) show that the first three weeks of July have already broken several significant records (ERA stands for “ECMWF Re-Analysis”; ECMWF stands for “European Centre for Medium-Range Weather Forecasts”).

C3S is implemented by the European Centre for Medium–Range Weather Forecasts with funding from the European Commission.

The month started with the daily global mean surface air temperature record being broken on four days in a row, from 3-6 July. All days since then have been hotter than the previous record of 16.80°C, set on 13 August 2016. The hottest day was 6 July, when the global average temperature reached 17.08°C, and the values recorded on 5 and 7 July were within 0.01°C of this. 

This means that the first three weeks of the month was the warmest three-week period on record. During the first and third weeks, temperatures also temporarily exceeded the 1.5°C threshold above preindustrial level – a limit set in the Paris Agreement. 

ERA5 data also show that the global mean surface air temperature for the first 23 days of July was 16.95°C. This is well above the 16.63°C recorded for the full month of July 2019, which is the current hottest July and hottest month in the ERA5 record. It is almost certain that, in due course, data will show July 2023 to break both these records. 

Contributing to the exceptionally warm July for the globe as a whole is a long period of unusually high sea surface temperatures (SSTs). Since April, the global average daily SST has remained at record values for the time of year. From mid-May onwards, global SSTs values have reached unprecedented levels for the time of year. According to ERA5 data, on 19 July, the daily SST value reached 20.94°C, only 0.01°C below the highest value ever recorded, of 20.95°C on 29 March 2016. 

Carlo Buontempo, Director of C3S, comments: “Record-breaking temperatures are part of the trend of drastic increases in global temperatures. Anthropogenic emissions are ultimately the main driver of these rising temperatures”. He added, “July’s record is unlikely to remain isolated this year, C3S’ seasonal forecasts indicate that over land areas temperatures are likely to be well above average.”