March records beaten as temperatures hit 30C in south-west France

Parts of south-west France saw records broken for the highest temperatures in March.

The mercury hit 30C in some parts on Wednesday (March 29), around 10-12C above the norms for the season.

It reached 30.1C in Dax, Mont-de-Marsan (both Landes) and Orthez (Pyrénées-Atlantiques). 

The previous records for March were: 

• Dax: 29.9C on March 21, 1990
• Mont-de-Marsan: 29.2C on March 21, 1990
• Orthez: 29C on March 31, 2021.

Patrick Galois, a forecaster at Météo France, told AFP: “This is the first time that this [30C] threshold has been reached on the mainland this year.”

The 30C threshold has only been broken twice in March in metropolitan France: In Pau, on March 25, 1955 (31C), and in Figari on March 24, 2001 (30.3C).

️ Records* mensuels de T°C max battus ce #29mars ⬇️

DAX (Landes) : 30.1°C (29.9°C le 21/03/1990)
MONT-DE-MARSAN (Landes) : 30.1°C (29.2°C le 21/03/1990)

Premiers 30°C en 2023

⚠️*liste non exhaustive après analyse des valeurs, stations avec ➕de 30 ans de données

⬇️ https://t.co/dZP2Khrslf

— Météo-France (@meteofrance) March 29, 2023

The warm temperatures were caused by an Atlantic depression, which brought an anticyclone weather pattern over France, making hot air rise across the country in southerly currents. 

The impact was also increased by the ‘Foehn effect’, which is when a mass of air suddenly reheats after passing over a mountain range (the western Pyrenees).

National records

Other towns also broke temperature records on Wednesday.

• Clarac, Haute-Garonne: 27.5C vs 26.5C
• Villefranche-de-Rouergue, Aveyron: 26.2C vs 26C
• Belves, Dordogne: 26.6C vs 26.3C.

Across the rest of France, temperatures were still a solid 6-8C higher than the seasonal norms. 

• Clermont-Ferrand: 25C
• Nevers: 23C
• Paris: 21C (10C higher than the day before).

Records mensuels de #chaleur battus ce 29 mars 2023 au sud-ouest :

➡ 30,8°C à Lagor (64)
➡ 30,4°C à Orthez (64)
➡ 30,1°C à Dax (40) & Mont-de-Marsan (40)
➡ 30,1°C à Captieux (33)
➡ 29,4°C au Houga (32)
➡ 28,7°C à Saint-Martin-Curton (47)
➡ 27,6°C à Dourgne (81) pic.twitter.com/4dW6Zvxoc5

— Guillaume Séchet (@Meteovilles) March 29, 2023

Biarritz’s balmy night

Biarritz registered its warmest night on Tuesday/Wednesday with a minimum of 18.9C. This broke the previous monthly minimum of 18.2C, from March 4, 1998. 

Cold front approaching

The high temperatures will not last: a cold front is forecast for the end of the week and into the weekend, which will bring temperatures plummeting downwards again, said Météo France.

From today (Thursday, March 30), high pressure will move towards the east, and inclement weather is forecast for tomorrow (Friday, March 31).

Forecaster Mr Gallois said: “Temperatures will start to drop dramatically, to come back to the norms of the season by Friday, and this weekend we will even go under the norms for the start of the month of April.” 

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