September 2023: A Record-Breaking Month in Global Warming Trends
The most current data on global warming from the Copernicus program signals an alarming rise in temperatures, surpassing all prior years. Officials responsible for this European Union monitoring effort note that September 2023 is on track to become the hottest September in recorded history, likely the warmest year yet. The overall trend points to a long-term increase in temperatures far beyond recent decades, with records appearing to fall month after month.
Sep tember 2023 already set new benchmarks for warmth, leading both air temperature and sea surface temperature metrics. It was also the month when Antarctica lost the greatest amount of its frozen mass on record. All charts clearly show how sharply the latest month deviates from earlier months that were already trending upward.
Specifically, the average surface air temperature in September was measured at 16.38°C, which is 0.93°C above the 1991-2020 average for that month and 0.5°C above the September temperature of 2020, previously the record holder. This marks the hottest September in history.
1.75°C rise versus pre-industrial times
When compared to the pre-industrial baseline commonly used to assess climate change, September 2023 shows an increase of 1.75°C above the 1850-1900 average. In essence, at least for September, humanity has already surpassed the 1.5°C threshold established by the Paris Agreement. While it may be temporary in nature, this marks the first instance of such a concerning level of warming.
In the broader annual frame, the January–September period registered a total temperature increase of 1.40°C relative to pre-industrial averages.
September 2023 versus the 1850–1900 average: a 1.75°C jump
Samantha Burgess, Deputy Director of the Copernicus Climate Change Service (C3S), commented that September exhibited unprecedented temperatures for that time of year. After a historically hot summer, records were surpassed by a wide margin. This extraordinary situation means September 2023 stands as the warmest September on record, with the year as a whole likely to be the warmest yet, approximately 1.4°C above pre-industrial levels. With two months left before COP28, the call for ambitious climate action has never been more urgent.
Europe surpasses the global average
Europe experienced higher increases than the global average, highlighting a pronounced warming trend across the continent, especially in the Mediterranean region. Copernicus notes that September 2023 in Europe was about 2.51°C above the 1991–2020 average, and it was 1.1°C hotter than the previous record set in 2020.
Additionally, sea surface temperatures in September reached a record high of 20.92°C, marking the warmest September on record since temperature records began and the second highest temperature for any month, only behind August 2023.
Meanwhile, ice loss in Antarctica continued to advance, contributing to rising global sea levels. Copernicus reported that both daily and monthly ice volumes reached their lowest annual maximum values in September, with the monthly ice area about 9% below the long-term average. Daily Arctic sea ice extent reached its sixth annual minimum, and monthly extent ran about 18% below average, ranking as the fifth lowest on record.
Further month-by-month data are available from Copernicus climate bulletins, which provide ongoing analysis of these trends.
Notes about data will continue to be updated as the monitoring system tracks evolving climate indicators and extreme events across the globe.