Europe’s Summer of 2003 Set Records

The summer of 2003, when there were more than 19,000 deaths attributed to the heat, probably was the hottest in Europe in 500 years, according to an analysis of temperatures dating back to 1500.

“When you consider Europe as a whole, it was by far the hottest,” said Jurg Luterbacher, climatologist and the first author of a study appearing this week in the journal Science.

Luterbacher, a researcher at the University of Bern, Switzerland, said increased temperatures were not limited to summer in Europe. Winters also have been warmer than the historical record.

In the study, Luterbacher and his team analyzed the temperature history of Europe starting in 1500 to the present. For the earliest part of the half millennium, the temperatures are estimates based on proxy measures, such as tree rings and soil cores. But after about 1750, he said, instrumented readings became generally available throughout Europe.

During the 500 years, there were trends both toward cool and toward hot. The second-hottest summer in the period was in 1757. That was followed by a cooling trend that continued until early in the 20th century.

Record temperatures were recorded in most of the major cities of Europe last year, with many readings of more than 100 degrees. Authorities have attributed thousands of deaths to the excess heat, making the heat wave one of the deadliest weather phenomena in the past century.