Scientists said last month that July was on its way to becoming the globe's hottest month on record, and that forecast came true.
The Copernicus Climate Change Service (C3S) announced Tuesday that July was the world's hottest month on record in terms of average surface air temperatures, while average sea surface temperatures also hit new highs.
The global average surface air temperature was 0.72 degrees Celsius (1.29 degrees Fahrenheit) warmer than the 1991-2020 average for July, the C3S said. Plus, the month was 0.33 degrees C (0.59 degrees F) warmer than the previous hottest month on record – July 2019.
They added that July was estimated to have been about 1.5 degrees C (2.7 degrees F) warmer than the average for 1850-1900. This 1.5-degree C threshold was set by the Paris Climate Agreement as the target limit for climate change over 20- or 30-year periods.
According to the C3S, heat waves occurred throughout the Northern Hemisphere, while well-above-average temperatures occurred over several South American countries and in much of Antarctica.
Land and sea
In addition to the global average surface air temperatures, the global average sea surface temperatures were also record-setting in July.
For the month as a whole, global average sea surface temperatures in July were 0.51 degrees C (0.92 degrees F) above the 1991-2020 average. The C3S noted how these temperatures came after a long period of unusually high temperatures since April 2023.
The North Atlantic was 1.05 degrees C (1.89 degrees F) above average in July, as temperatures in the northeastern part of the basin remained above average, the C3S said. Plus, unusually high temperatures developed in the northwestern Atlantic.
Just as heat waves occurred on land, they also occurred in the sea. According to the C3S, marine heat waves happened south of Greenland and in the Labrador Sea, in the Caribbean basin, and across the Mediterranean Sea.
"We just witnessed global air temperatures, and global ocean surface temperatures set new all-time records in July," said Samantha Burgess, deputy director of the C3S. "These records have dire consequences for both people and the planet exposed to ever more frequent and intense extreme events."
The C3S added that the global mean temperature for 2023 so far is currently the third-highest on record at 0.43 degrees C (0.77 degrees F) relative to the 1991-2020 period.
In comparison, the highest global mean temperature for the calendar year occurred in 2016 at 0.49 degrees C (0.88 degrees F) above average. The second-highest global mean temperature occurred in 2020 at 0.48 degrees C (0.86 degrees F) above average, according to the C3S.