Ellen Phiddian
Cosmos science journalist
The world has once again seen its hottest day on record, toppling the previous high from 2023. The record might already have been broken.
The European Union’s Copernicus Climate Change Service (C3S), which uses satellite data to monitor global weather conditions, has recorded a new global high of 17.09°C.
Prior to July last year, world average temperatures hadn’t breached 17°C since monitoring began 200 years ago. The previous hottest day was 13 August 2016, with a temperature of 16.80°C.
In the last 13 months, that 2016 record has been exceeded on 57 days.
The 17.09°C record, recorded on 21 July 2024, beats the previous record of 17.08°C, logged on 6 July 2023.
C3S, which is a facet of the European Union’s Earth-monitoring space program Copernicus, uses a group of satellites to track a range of climate indicators, such as temperature, precipitation, and soil conditions, all over the world.
The service releases preliminary data a few days after it’s recorded, which is where the 21 July record comes from.
C3S then confirms and cleans its dataset, by comparing observations to those coming from other satellites, global weather stations, and other instruments, and releases the more accurate version a couple of months later.
Based on its modelling and further observations, C3S is expecting the average temperature to rise again, forecasting a peak on 22 or 23 July.
“We are now in truly uncharted territory and as the climate keeps warming, we are bound to see new records being broken in future months and years,” said C3S director Carlo Buontempo in a statement.
Global average temperatures tend to rise during the Northern Hemisphere summer, because the larger landmasses heat up faster than the oceans in the south. This means that the warmest days of the year usually fall between late June and early August.
Thanks to an El Niño event in the Pacific Ocean, the latter half of 2023 was warmer than average, leading to 2023 being the hottest year on record.
It’s not yet clear if 2024 will beat this record. While the current heatwave puts 2024 in the running, there may be weather patterns later in the year that reduce the heat.
Current models, such as the Australian Bureau of Meteorology’s, are tentatively predicting El Niño’s cooler counterpart La Niña to develop in coming months.
But, driven by climate change, recent La Niña years have still been some of the hottest on record.
“We’re seeing such extremes more often and we simply cannot ignore the risks to humans, to our environment, to our businesses and our industries,” says Professor Deanna D’Alessandro, director of the University of Sydney’s Net Zero Institute.
