For the second year in a row, summer in the Northern Hemisphere ranked as the warmest on record with extreme heat bringing persistent, dangerously hot conditions.

The Climate Change Service (C3S) of Copernicus, the climate monitoring component of the European space program, reported Friday that this year’s boreal summer was the hottest on record for the planet since measurements have been available.

Scientists say human-caused climate change, with a temporary boost from El Nino, keeps dialing up temperatures and extreme weather.