Splish-splash! Parisians and tourists soak in the Seine

At the foot of the Eiffel Tower, swimmers were doing the breaststroke, chatting, or resting on their yellow floaters -— mandatory because of the current -— under the watchful eye of lifeguards in fluorescent T-shirts.

"It's better than the pool; it's not quite the beach, but it gives you the feeling you're already a little bit on holiday," said Lauriane Fiorentino, an employee at a construction company.

Sunbathers dotted the riverbank, adding to City of Light's charm.

"Look at this water, with the Eiffel Tower in the background ... Honestly, can it get any more beautiful than this?" marvelled American Benjamin Doncan.

Paris sweltered in late June during a heatwave that roasted much of Europe, sending temperatures soaring to 40C and above in some corners of France, with forecasters warning that another heatwave may be possible in coming weeks.

Air conditioning is not widespread in residential homes in the French capital, making swimming one of the most popular ways to cool off.

A century-long ban on swimming in the river snaking through Paris was lifted for the 2024 Olympics.

Since then three sites staffed by lifeguards have been opened to swimmers during the summer months.

The sites, which are free of charge and drew nearly 100,000 visitors last year, will remain until the end of August.

They are located in Bercy in the east near the finance ministry, Grenelle in the upscale west and Bras Marie, in the heart of Paris.

The water quality, which heavily depends on the weather, is tested several times a day and indicated to swimmers with a system of green, orange and red flags.

"I was a bit scared, but they do tests every morning," said Pierre Aboukrat, an employee at the town hall of the 15th district.

"Then I'm careful, I don't swallow any water ... It's safe, so it's fine," he said.