PARIS (BLOOMBERG) - Paris is facing one of its worst heatwaves in more than a century, with daily average temperatures hovering around 30 deg C over a seven-day period and hitting a maximum of 39 deg C on Sunday (Aug 9), according to forecaster Meteo-France.

The hot weather will last through the middle of next week, creating the worst heatwave conditions in the French capital since the 2003 scorcher that lasted 10 days, Meteo-France meteorologist Francois Jobard said in a tweet on Friday.

"Other than 2003, the capital therefore begins its most dreadfully hot week since 1873," Mr Jobard said.

The Paris region's prefect, the chief administrative official, on Thursday declared a heatwave alert, activating measures such as delivering fans to vulnerable people and handing out water bottles to the homeless.

After the 2003 heat wave killed an estimated 15,000 people in France, the country introduced a "plan canicule" to limit the impact of episodes of hot weather.

The city of Paris last year introduced a free app called Extrema Paris that allows Parisians to locate green spaces, bathing spots, churches and other cool spots.

Meteo-France has declared a heatwave alert for about half of the country, with temperatures in the south-west locally forecast to top 40 deg C on Friday, before temperatures there start to fall again on Saturday.

Heatwaves in France have become more frequent and more intense in the past 30 years, and climate change means their number and duration is expected to increase further in the 21st century, according to Meteo-France.

The country is already experiencing unusually warm weather, registering its 14th consecutive month of above-normal temperatures in July and the warmest January-July period since 1900.