The European Union's Earth Observation Programme said Wednesday that the Earth's surface was warmer last month than during any September on record, with temperatures since January closely matching those of the hottest ever calendar year in 2016.
According to the Copernicus Climate Change Service, this year has now seen three months of record warmth -- January, May and September -- with June and April virtually tied for first.
"There is currently little difference between 2020 and 2016 for the year-to-date," Copernicus senior scientist Freja Vambourg told AFP.
For the 12-month period through September, the planet was nearly 1.3° Celsius above pre-industrial levels.
That is alarmingly close to the 1.5°C threshold for severe impacts detailed in a major 2018 report by the UN's climate science advisory panel, the IPCC.
The 2015 Paris Agreement has enjoined nations to cap global warming at "well below" 2°C, and 1.5°C if feasible.
Steady rise in global temperatures
So far, Earth has warmed on average by one degree, enough to boost the intensity of deadly heatwaves, droughts and tropical storms made more destructive by rising sea levels.
Climate change driven by greenhouse gas emissions from burning fossil fuels has picked up pace in recent decades.
Nineteen of the last 20 years have been the warmest since accurate readings began in the late 19th century.
Since the late 1970s, the global thermometre has crept up 0.2°C every decade, according to EU data.
Freakish and brutal
Temperatures in September were "exceptionally high" over northern Siberia, which -- along with much of the Arctic Circle -- has seen freakishly warm weather for months.
September was brutal in the Middle East, with new high temperatures reported in Turkey, Israel and Jordan.
Parts of North Africa and Tibet were also scorching hot, while maximum daytime values reached 49°C in Los Angeles County early in the month.
Across California, five of the state's six biggest wildfires in history were still burning at the end of the month.
"September was warmer by 0.05°C than September 2019, the previous warmest September," the Copernicus report said.