August starts in sweltering heat after France's 3rd hottest July for century

July this year was France's third hottest for over a century and August has started even hotter. As temperatures soared as high as 9°C over the seasonal average, forecasters warned of storms across much of the country.

Australian tourist Caitlin sunbathes on the beach at Cannes on the last day of July Reuters/Eric Gaillard

Only July 2006 and July 1983 were hotter than last month, weather-watcher Météo-France reports.

This year's spring, the coldest on record, aroused fears that summer would be rained off.

But, after a cool start, temperatures soared in July and August has started in a blaze of thermometer glory.

Temperatures in Bordeaux on Thursday hit 37°C, 9°C higher than usual, 34°C in Lyon, 5°C higher than usual, and 35°C in Paris.

They syated high on Friday but officials have yet to declare a heatwave, which must see high temperatures for three consecutive days.

Nevertheless, the authorities are acting to prevent a repeat of the massive mortality rate during the 2003 heatwave, Interior Minister Manuel Valls said on a visit to the south-western Landes region Thursday.

Paris city council has started contacting the 20,000 elderly or handicapped people who have put their names down to be monitored when the temperature rises.

The health ministry advises people to drink between one and one and a half litres a day, while avoiding alcohol, tea, coffee and sodas, which dehyrdrate the body and to stay indoors when the temperature is highest.

Météo France warned of more summer storms moving across the country from the Basque Country in the south-west to Champagne-Ardenne in the north-east on Friday.

They may not last long, the forecasters warned, but they could bring hail, high winds and heavy downpours.

A teenager died Thursday after falling into a deep, icy lake in an old quarry in the Val d-Oise, near Paris.

Bathing is strictly forbidden in the Lac des Ciments, also known as the "Blue Lake", but several deaths have occured there, most recently that of a young man who could not swim in June.