French weekend weather forecast September 20 - 21: storms return but temperatures stay high

Storms are set to sweep across France this weekend, with the south-west and the Rhône Valley most affected, though temperatures will stay above average in most areas. 

In Normandy, Brittany, and Hauts-de-France, sparse showers and clouds are expected rather than full storms, although all other regions are likely to see a fair amount of rainfall.

Friday September 19 

Friday will be the peak of the warm and peaceful week to date. 

Highs of up to 35C in the south-west, and 30C or more in much of the north and centre of France will be complimented by clear skies. 

Cloudy weather is expected in Brittany and Normandy, but rain is unlikely. 

However, Atlantic storms will move into the west of France overnight, hitting Nantes and moving along the Loire. 

Saturday September 20 

Storms will move eastwards, reaching the north of France in the morning before moving through the centre and the south-west by the afternoon. 

Thunder is possible alongside rain, however temperatures are set to remain high, up to 25C in areas affected in the north and 30C in the south-west. 

Note however this is not as high as on Friday, which is set to be the warmest day for the rest of 2025.

Currently, several less-severe tier-two yellow alerts are in place by state forecaster Météo France along the storms’ expected route, but no heightened alerts have been raised.

Elsewhere, the north will be cloudy and the Mediterranean and east remain warm, with only slight cloud coverage. 

Parts of the east will see highs around 8C warmer than usual for the season. 

The storms will weaken as the evening progresses.

Sunday September 21 

Early thunderstorms in the Pyrénées will move across the Massif Central and the Mediterranean coast before reaching the Rhône Valley, where lingering heat is expected to trigger heavy, muggy conditions.

Rain in the valley and Massif Central could measure well over 100 mm across the storms.

Storms are set to be violent and heightened warnings are likely to be declared on Saturday (Météo France only raises alerts one day in advance). 

Check local weather reports and the forecaster’s website.

Elsewhere, cloudy skies are expected over most areas, with intermittent showers in the east, south-west, and centre. 

Temperatures will drop, with highs of 20C unlikely to be seen except in the south-east. 

Early forecasts for next week see temperatures dropping further, with up to a 15C difference between Friday (September 19) and next Monday (September 22, which is also the autumn equinox).