A HOT spell enveloping Europe has pushed the zero-degree line – the altitude at which the temperature dips into the minus – to a record height of nearly 5,300m in Switzerland.  

The zero-degree line is determined by meteorologists using weather balloons that take off twice a day from Payerne in western Switzerland.  

MeteoSwiss said the new height was clocked overnight from yesterday to today at 5,298m, “which constitutes a record since monitoring began in 1954”. 

The previous record of 5,184 metres was set on July 25 last year.  

“The area known as the zero-degree isotherm is the threshold between air layers with temperatures above 0°C at lower altitudes and those with temperatures below freezing at higher altitudes,” MeteoSwiss said.  

“Among other things, the zero-degree isotherm affects vegetation, the snow line and the water cycle, and so has a considerable impact on the habitats of humans, animals and plants alike,” it added, calling the marker “an integral part of weather forecasts in the Alpine region”. – AFP, August 21, 2023.