Data from the European Union’s Copernicus Climate Change Service reveals September 2023 as the hottest ever recorded, marking four consecutive months of unprecedented heat. This 0.5°C rise above the 2020 record pushes 2023 towards being the hottest year ever. Copernicus’ Samantha Burgess called this “unprecedented for the time of year,” raising concerns about global climate goals and extreme weather events.

September felt more like a sweltering July, with a global air temperature averaging 16.38 degrees Celsius (61.45 Fahrenheit). This temperature was 0.93 degrees Celsius hotter than the 1991–2020 average and a whopping 1.75 degrees Celsius higher than the pre-industrial era September average. Such an increase far surpasses the 1.5-degree Celsius threshold established under the Paris Climate Agreement. September’s scorching heatwave has already provided a glimpse into the catastrophic consequences of surging temperatures, resulting in deadly floods in Libya, Greece, Bulgaria, and Turkey, an unprecedented wildfire season in Canada, and record-breaking heatwaves in South America. Additionally, sea surface temperatures in September reached an unprecedented 20.92 degrees Celsius (69.66 Fahrenheit), while Antarctic sea ice hit record lows. Climate scientist Zeke Hausfather summed up the situation as “gobsmackingly bananas.” With European countries experiencing record-breaking temperatures even in October, it is increasingly likely that 2023 will indeed claim the title of the hottest year ever recorded, leaving policymakers with a stark wake-up call as they prepare for the United Nations COP28 climate summit in December. The urgency to phase out fossil fuels and address human-caused climate change has never been clearer.