Meteorologists say 'unusual' heatwaves now becoming norm
In a joint statement – meteorologists from Switzerland, Germany and Austria say heatwaves which were considered unusual in the 1990s are now becoming the norm.
The forecasters say the change is a clear sign of climate change.
A heatwave is described as 14 consecutive days with an average temperature above 30 degrees and nights of above 20.
A heatwave in major cities was expected every 4 years on average, now its every 2.
The forecasters say they expect that to continue.
Weather records from all three countries date from the mid to late 1800s – except for Austria, which has accurate numbers from 1767.