Will the Seine be clean enough by the Olympics? Not even the experts know yet

Paris only experienced one weeklong dry spell this year, in early June, whereas between 1950 and 2020, it was typical for the city to have at least three such periods by the end of June, according to the analysis.

“Predictions of rainfall have become much more accurate up to a week in advance,” said Jennifer Francis, a scientist at the Woodwell Climate Research Center in Massachusetts. “But the seasonal patterns of past decades no longer provide reliable guidance in our warmer world.”

With the Games approaching, the feverish debate over the cleanliness of the Seine River has become a source of frustration for some athletes like Léonie Périault, a French triathlete who won a bronze medal in the 2020 Tokyo Olympics.

“Every time I meet someone, they worry that I’m going to swim in the Seine,” Périault said. “But I’ve been swimming in this river for several years now. In youth competitions, we swam regularly in the Seine and never had problems.”

Last year, Périault took part in a test event in the Seine.

“The setting was incredible with the Eiffel Tower as a backdrop and the water conditions were not worse than anywhere else in the world,” she said.