'Zero-degree line' rises to record height as heatwave continues in Europe
Aug. 21 (UPI) -- Switzerland's MeteoSuisse reported another measure of record summer heat Monday when its weather balloon climbed to a record-high 17,400 feet before reaching what it calls the zero-degree line.
The zero-degree line, which is the altitude at which the temperature falls below freezing, is considered a key meteorological marker, particularly in mountainous regions, has been climbing and set a record in 2022.
"The Payerne, [Switzerland] radiosounding this night from August 20 to 21, 2023 measured the 0°C isothermal 5,298 meters, which is a record since the start of measurements in 1954," MeteoSuisse said in a translated social media post.
Le radionsondage de Payerne de cette nuit du 20 au 21 août 2023 a mesuré l'isotherme du 0 °C à 5298 m ce qui constitue un record depuis le début des mesures en 1954. Le précédent #record datait seulement du 25 juillet de l'année dernière avec 5184 m. #meteosuisse #canicule pic.twitter.com/dWjnKIRQ7r— MétéoSuisse (@meteosuisse) August 21, 2023
The weather service said the zero-degree line "affects vegetation, the snow line and the water cycle so has a considerable impact on the habitats of humans, animals and plants alike."
The zero-degree line averaged 8,432 feet from 1991 to 2020, with a high of about 13,123 feet in the summer.
"Anthropogenic climate change has caused the altitude of the zero-degree line to rise significantly in every season,"MeteoSuisse said.
From Greece to Portugal, Europe has been facing unprecedented wildfires sparked by record-high temperatures around the continent. Hundreds were forced to evacuate around Portugal's southern region of Algarve because of wildfires there earlier this month.
Also in August, Greek Prime Minister Kyriakos Mitsotakis said his country would provide a free week's holiday on the island of Rhodes in 2024 to the thousands of tourists forced to leave there in July because of wildfires.
About 20,000 mainly British tourists were forced to evacuate or sleep on gymnasium and school floors because of the raging fires.
