France’s new fifth heatwave: how long will it last and temperatures expected

Temperatures will steadily climb throughout the week as France sees its record fifth heatwave of the year arrive.

A ‘heat dome’ effect over much of the country will bring intense temperatures of well over 35C across almost the entire country. Only the coastal regions of Normandy and Brittany, as well as the Alps are set to see highs limited to 30C or below. 

Reaching a peak on Thursday, conditions are set to last until the start of the weekend, when the dome is punctured and clouds bringing persistent rain cover France.

However, this will not be accompanied by any cooler or fresh winds, which could take up to two weeks to arrive.

This delay to cooler air arriving, forecast by 'Predict Services' (the risk arm to state forecaster Météo France), means 'very dry air' will remain present in the air for the coming week, said the group's president Alix Roumagnac.

There are also concerns that the heatwave will exacerbate drought conditions across France, which now see restrictions or warnings over tap water usage in every department of mainland France.

Unlike previous heatwaves, overnight temperatures should be slightly cooler, mitigating some of the worst effects of the hot weather. 

Monday August 10 

The week begins with several departments already facing heightened heatwave warnings, and the majority of departments on a yellow tier-two warning for heatwave conditions. 

Highs of 30C are forecast in the north and south-west, slightly higher along the Mediterranean, but in the east temperatures of 35C are possible. 

Tips on how to stay cool are available here, and information on signing up vulnerable residents (either yourself or relatives) to local heatwave registers can be found here.

A bout of storms is also forecast for Monday, running from the south-west up to the German border. Beginning in the morning in the south-west, they will run up the course of France across the day, and last well into the evening along the Rhine. 

However, no heightened warnings for storms have been given by state forecaster Météo France. 

Tuesday August 11 

Temperatures will continue to climb in the north (up to 30C north of the Seine, and 35C north of the Loire) and the south-west (34C in Toulouse, 36C in Bordeaux). 

Official temperature recordings are given in the shade so when outside in direct sunlight it can feel far hotter. 

Storms will continue in the south-east, running roughly from Hérault up to the Alps and along the Rhône Valley. 

Highs of over 35C are forecast in the valley despite the storms, with temperatures of 30C and above expected in other stormy areas. 

Wednesday August 12 

A further rise in temperatures will see highs of 35C widespread across the north, closer to 40C along the Loire Valley. 

In the south, highs of 38C are expected in Lyon, Bordeaux, and Toulouse. 

The day will be sunny and calm, with only brief storms – not set to be powerful – forecast in the Alps. 

Despite intense daytime temperatures, overnight conditions should be cooler, with the north seeing temperatures drop below 20C, and much of the south-west and centre seeing temperatures of 20C - 23C. 

It is only the Mediterranean coast where temperatures are set to remain consistently above 23C overnight, although this is fairly common for the area during summer. 

These temperatures will allow homes and people to cool down overnight, lessening the impact of daytime heat. 

Thursday August 13 

Another increase in temperatures is forecast, and could see highs of 40C along the Loire and Rhône Valleys and in the south-west. 

Paris may reach 38C, with most of the country seeing temperatures of 35C or above. 

This will make it the hottest day of the heatwave.

Conditions will again remain calm and sunny, despite a small risk of storms in the Alps. 

Friday August 14 

A drop of 1C or 2C in most areas will make Friday slightly cooler, but heatwave conditions are still expected across all areas. 

More significant temperature drops will take place in Brittany (where highs of 26C rather than 30C are forecast), parts of the centre, and the south-east. 

Rainfall is expected across several areas – although models are yet to accurately predict its path, it is currently forecast in the capital and south-east – bringing some relief. 

By Saturday, this rainfall will spread to cover most of France, helping further cool temperatures and puncture the heat dome with cooler air. 

Sunday should see the end of the heatwave, with renewed rain and temperatures failing to reach 30C in any region.