The Copernicus Climate Change Service (C3S) has announced that global temperatures for September 2020 were higher than in any previous September on record.
C3S reanalysis data shows that the month was 0.63°C above the average September temperatures of the standard 30-year climatological reference period (1981-2010).
This makes September 2020 0.05°C warmer than September 2019, and 0.08°C warmer than September 2016, previously the warmest and second warmest Septembers. C3S is implemented by the European Centre for Medium-Range Weather Forecasts (ECMWF) on behalf of the European Commission, and monitors global and European climate.
Across Europe, September average temperatures also reached a record high, about 0.2°C warmer than the previous warmest September of 2018. Much of the continent saw above average temperatures for September, especially southeastern Europe.
C3S scientists also noted that both 2016 — the warmest calendar year recorded to date — and 2020 currently show little deviation in terms of year-to-date figures, meaning that the average global temperature anomalies between January 1 and September 30 of these two years are fairly similar; 2020 is warmer than 2019 for the same period, however, climate patterns such as La Niña will influence whether 2020 becomes the warmest year on record.
In the Siberian Arctic, temperatures continued to be warmer than average in September, continuing a warm spell that has affected different parts of the vast region since early spring. Although Siberia and the Arctic have large temperature fluctuations from year to year, it is noted that the relative warmth observed this year has been unusual in its magnitude and persistence.
C3S also monitors sea ice on a monthly basis and its data confirmed that the average Arctic sea ice extent for September was the second lowest recorded, after September 2012. In the Arctic, sea ice extent has declined markedly since 1979 when satellite observations began. The trend can be seen for all months of the year but especially in September, the time of year when the ice cover reaches its annual minimum.
Carlo Buontempo, Director of Copernicus Climate Change Service at ECMWF, explained., “In 2020, there was an unusually rapid decline in Arctic sea ice extent during June and July, in the same region where above average temperatures were recorded, preconditioning the sea ice minimum to be particularly low this year.
“The combination of record temperatures and low Arctic sea ice in 2020 highlight the importance of improved and more comprehensive monitoring in a region warming faster than anywhere else in the world.”
C3S publishes monthly climate bulletins reporting on the changes observed in global surface air temperature and other climate variables. All the reported findings are based on computer-generated analyses using billions of measurements from satellites, ships, aircraft and weather stations around the world.