France registered its highest temperature since records began on Friday as the death toll rose from a heatwave suffocating much of Europe.

The mercury hit 45.1 degrees Celsius in Villevieille, in the southerly Provence region, the weather forecaster Meteo France said, a whole degree above the previous high of 44.1C recorded in August 2003.

The World Meteorological Organization said 2019 was on track to be among the world's hottest years, and that 2015-2019 would then be the hottest five-year period on record.

It said the European heatwave was “absolutely consistent” with extremes linked to the impact of greenhouse gas emissions.

Four administrative departments in France were placed on red alert, signalling temperatures of “dangerous intensity” that are more typical of Saudi Arabia.

Temperatures in parts of Spain were expected to hit a new June record of 43C.

Since 1975, Spain has registered nine heatwaves in June. Five of them, however, have been in the last decade, according to the Spanish meteorological office.

In Catalonia, northeast Spain, wildfires were raging across 60 sq kilometres of land, but firefighters said that area could quadruple. Farmers were asked to stop all work across the region for 48 hours.

In the city of Valladolid in central Spain, a man of 93 collapsed and died due to the heat, police said. And in a small town outside Cordoba, a 17-year-old died of heat-related effects after jumping into a swimming pool to cool off after a day working in the fields, regional health authorities said.

In France, one boy was seriously hurt when he was thrown back by a jet of water from a fire hydrant. Some 4,000 schools were either closed or running a limited service to help working parents unable to stay at home.

French families with elderly relatives who were ill or living alone were advised to call or visit them twice a day and take them to cool places, while the state-run rail operator SNCF offered free cancellations or exchanges on long-distance trips.

The greater Paris region, Ile de France, had already banned more than half of cars from its roads as the stifling heat worsened air pollution, the toughest restriction provided for — although all cars were to be allowed to leave the city as school holidays began. The cities of Lyon, Strasbourg and Marseille have also restricted traffic.

The unusually high temperatures are forecast to last until early next week.