French heatwave update: highs of 40C with temperatures climbing tomorrow

France’s record fifth heatwave enters its most intense spell today (August 12), with temperatures of 40C possible from the Loire Valley to Corsica. 

Temperatures of 24C to 26C were already recorded across Brittany at 05:00 this morning, with most areas seeing thermometers remaining above 20C overnight. 

A high of 40.6C was recorded in Corsica yesterday, alongside peaks of 39C in Indre-et-Loire and Cher. 

State forecaster Météo France has placed 78 departments on a heightened tier-three orange warning for heatwave conditions today, rising to 80 tomorrow (August 13). 

By Thursday, every mainland department will face at least a tier-two yellow warning for heatwave conditions. 

We recently answered several popular heatwave-related questions, including on how to keep pets safe, installing air conditioning, and driving rules. Read our article here for more.

Further climb expected tomorrow

The official forecaster has not indicated that it will raise red-level alerts – the highest possible for heatwave conditions – as these require extreme day- and night-time temperatures to be recorded for several days. 

However, La Chaîne Météo (owned by Le Figaro) has implemented its own red-alerts in four western departments due to the heat. These are Indre-et-Loire, Deux-Sèvres, Vienne, and Maine-et-Loire. 

While these alerts are not official, they do point towards extreme conditions in the area.

Forecasters are aligned however in believing that the most intense spell of the heatwave will last until Friday, and widely agree that temperatures will increase tomorrow.

Current predictions of 39C in the north, 40C along the Loire Valley, and up to 42C in the south-west are all in place for Thursday. 

Indeed, national average temperatures are expected to reach 28.6C on both Thursday and Friday. 

This is less than a degree off the previous all-time record of 29.4C, recorded in August 2003 and July 2019. However, it is worth noting that this record is likely to have been surpassed several times this year during the June heatwaves.

The extreme heat is largely caused by a ‘heat dome’ effect, with a mass of warm air positioned over much of France. It is preventing cooler air from entering the atmosphere, as well as trapping radiation attempting to leave overnight, both of which cause temperatures under the dome’s effect to steadily rise. 

While the north of the country will see heatwave conditions end by the start of the weekend, they will persist until potentially Monday (August 17) in the south.

Early forecasting models point towards considerably cooler temperatures next week, which will see national average temperatures drop below August averages for several days. 

However, this may not be accompanied by refreshing cool winds, which models say may take an extra week to appear in the atmosphere.