More than 90 percent of weather stations studied showed the climate was warming, a percentage too high to purely be from natural climate variability, say researchers.

Europe has been roasting this summer. And last summer. And ... well, according to new research, the number of summer days with extreme heat has tripled since 1950. Summers have become hotter overall, they found, while the number of winter days with extreme cold decreased in frequency by at least half.

The research, published by American Geophysical Union, found that parts of Europe are warming faster than climate models have projected. With more than 90 percent of the weather stations in the study showing the climate was warming, the percentage is too high to be purely a product of natural climate variability.

"Even at this regional scale over Europe, we can see that these trends are much larger than what we would expect from natural variability. That's really a signal from climate change," said Ruth Lorenz, a climate scientist at the Swiss Federal Institute of Technology in Zurich, Switzerland, and lead author of the new study.

For the study, Lorenz and her team looked at observational data from European weather stations from 1950 to 2018 and then analyzed the top 1 percent of the hottest heat extremes and highest humidity extremes, and the top 1 percent coldest days during that period.

"We looked further at the hottest day or coldest night per year, so for each year we looked for the maximum/minimum value and how these changed over time," Lorenz said.

They found that the extremely hot days have become hotter by an average of 4.14 degrees Fahrenheit (2.30 degrees Celsius) while extremely cold days have warmed by 5.4 degrees Fahrenheit (3.0 degrees Celsius) on average.

They also concluded that the area was warming faster than climate models projected, with some regions having higher extremes than expected and some with lower extremes that expected.

Satellite image of heat energy emitted from Europe during 25 July 2019 showing summer's highest extremes. (Copernicus Sentinel data (2019) ESA - Copernicus Sentinel)/Public Domain

"In the Netherlands, Belgium, France, the model trends are about two times lower than the observed trends," said Geert Jan van Oldenborgh, a climate analyst at the Royal Netherlands Meteorological Institute in De Bilt, Netherlands (and who was not a part of the research). "We're reaching new records faster than you'd expect."

The study can be read here: Detection of a Climate Change Signal in Extreme Heat, Heat Stress, and Cold in Europe From Observations.