Highs of 35C in south-west France before sharp drop midweek

A burst of hot weather at the start of the week will bring temperatures of well over 30C across the south, with highs of 35C in the south-west and western Mediterranean.

The conditions are caused by a high-pressure anticyclone system from the Atlantic, which began to cover France over the weekend. 

The system will move southwards and cool wind will blow in from the British Isles on Wednesday, causing temperatures to fall quickly, in some places by around 10C.

The end of the week should see conditions stabilise although a lack of any significant rain for another week remains a concern as France’s drought woes worsen. 

Monday September 14 

The start of the week will be the sunniest and calmest, if not the warmest. 

Thick clouds north of the Seine will clear by late morning with the area joining the rest of the country in sunshine. 

Highs of 23C - 25C in the north-east and near the German border quickly reach 28C around Paris, up to 29C in Nantes and Rennes. 

Highs of 30C are expected south of the Loire, rising to 33C around Bordeaux and 34C near Montpellier. 

Overnight temperatures will be warmer than in recent days, reaching close to 20C in parts of the south, but cool enough for homes and people to cool down. 

Tuesday September 15 

The high-pressure anticyclone system will begin to move south, covering the south-west fully but allowing cloudy conditions to sweep in north of the Loire.

In the south-west, highs of 35C are forecast, well above average for the season, and remaining up to 32C across much of the centre of France.

Temperatures will drop 1C to 3C in the north due to the removal of the anticyclone but will still be above average for the season. 

Indeed, the national average temperature on Tuesday is set to be 22.4C, only 0.5C off the maximum recorded during the heatwave at the start of the month and around 5C above average for mid-September.

Wednesday September 16 

The high-pressure system will leave the French atmosphere, bringing a sudden shift in conditions. 

A set of heavy, grey clouds will sweep in from the English Channel, and by afternoon reach the Mediterranean. 

These clouds are not set to bring rain, but will blot out the sunshine that was plentiful at the start of the week. 

Chilly winds will accompany the clouds, adding to the autumnal feel. 

Temperatures will drop by around 5C in the north and east and more sharply in the south-west with a fall closer to 10C, leaving highs of 24C to 25C in much of the area.

Montpellier is the only area likely to see temperatures of 27C or above. 

Thursday September 17 

Conditions will be similar on Thursday, with cloud coverage across most of the country – thicker in the north – and temperatures remaining at similar levels, dropping by 1C or 2C.

The national average temperature is forecast to be 16.7C, a drop of nearly 6C across two days, but dropping by as much as 10C in the south-west. It is the only day of the week where the national average temperature is set to be below seasonal norms.

Showers are forecast along the Normandy and Hauts-de-France coast, but will not penetrate inland and will remain weak and unlikely to impact drought conditions. 

Friday September 18 

There is a chance of morning rain across much of the north and centre of France but this will again be brief and light. 

Even if rain does fall, it will quickly disperse in all areas except the south-west where showers will persist into the afternoon in coastal areas – leading to another cloudy, but calm day across most of the country. 

Temperatures may rise by 1C to 2C, back to midweek levels, but a further burst of heat is not expected.

Early forecasts for the weekend see calm and sunny conditions and a continuation of the dry spell.