The previous record temperature of 33.4C (92F) in the Russian capital, a city with a continental climate, was set in 1996.

But it was broken Thursday with a temperature of 33.9C (93F), the Russian Meteorological Centre reported on its website Friday.

It added that a new record high was likely to be registered during the day, with weather services predicting temperatures of up to 36C (37F).

The heatwave was forecast to "persist" until early next week across central Russia and southern Europe, with temperatures "three to eight degrees above average climate norms", said the Russian Meteorological Centre.

The unprecedented heatwave saw Muscovites flocking to their suburban country houses, as well as to the capital's parks and fountains.

"It's hard, I'm taking medication," Valentina Aleksandrovna, 86, told AFP on a Moscow street.

The heat stress poses a particular challenge for workers on construction sites, as well as for the elderly.

The temperatures were "overwhelming," Aleksandrovna said, adding: "I don't remember ever experiencing such heat."

Some were swimming in the city's ponds and canals, despite the swimming bans warning of pollution in place.

"The water is dirty, look. We're here because it's easier to breathe near the water at 33 degrees," said Igor, 55, after taking a dip in Tushino, northwest of the capital.

"I've swum once, I doubt I'll go back," he told AFP, adding he had come to visit Moscow from the peninsula of Crimea, captured by Russia from Ukraine in 2014 at the start of fighting between Kyiv and Russian-backed separatists.

Scientists have long warned that climate change, driven by mankind's burning of fossil fuels, is making acute heatwaves, droughts, and other extreme weather events more frequent and more intense.

Western Europe experienced its hottest June on record last month, according to the EU's climate monitor Copernicus.