Scientists on board the icebreaker Polarstern have been without supplies for two months.
You probably wouldn't even notice the difference.
Thursday's reading beat the previous high of 17.5°C set in March 2015.
Copenhagen is known for its bikes and green outlook - but what are the latest ways the Nordic nation is trying to lead the way on cutting back on carbon? Greg Lory went to find out.
Potentially dangerous turbulence is becoming more common on transatlantic flights because of changes linked to climate change, according to a study.
June 2019 has just been confirmed as the hottest month ever on record, according to Copernicus.