France’s hottest day on record. 45 degrees in Spain

The special warning issued on Sunday remains in force overnight, with tropical minimum temperatures of 25 degrees and daytime maximum temperatures exceeding 45.

In France, 40 people have died after swimming in waters where bathing is prohibited, such as lakes, rivers and unsupervised canals. Around 1,800 schools have been closed due to the heat.

Today was the hottest day ever recorded in France, breaking the record set just 24 hours earlier, according to Météo-France. The national heat index, which is the average of day and night-time temperatures at 30 reference stations, reached 30 degrees, a level never before recorded.

In Germany too, the 40 degrees forecast for Friday 26th are expected to set a new heat record for June, whilst the United Kingdom came close to 40 degrees, approaching the record of 40.3 set in July 2022. A red alert is in place today for 300 schools, where an all-time temperature record cannot be ruled out. The heat is also being felt in the Netherlands, where Amsterdam is rolling out a network of ‘cooled’ zones across the city. Overall, according to the WHO, the temperatures being recorded across Europe at the moment constitute a public health emergency, following the heatwaves of the last four years which have caused over 200,000 deaths.

The extreme heat gripping Italy at the moment is accompanied, in the afternoons, by thunderstorms that do little to cool things down. Lorenzo Tedici, head of media meteorology at iLMeteo.it, confirms that these thunderstorms bring no real relief. The reason is purely physical: they are not associated with the passage of an Atlantic disturbance accompanied by cool air at high altitude (which would flow down towards the ground during the rainfall), but are generated exclusively by excess heat and the rapid saturation of water vapour in the atmosphere. In practical terms, these are effectively ‘hot showers’. During these showers, temperatures drop only slightly (by just 1–2°C), whilst the humidity in the air rises even further. The effect on our bodies is negligible: the perceived temperature remains the same, leaving the feeling of oppression and physical discomfort unchanged.

We can expect this afternoon’s unsettled weather to continue until tomorrow, 25 June. After that, the Caronte high-pressure system will strengthen further, preventing thunderstorms and making the atmosphere even more stable and sweltering. The peak of this very long and gruelling heatwave is expected between Sunday and Monday. The models confirm an extremely challenging biometeorological scenario, especially for central and northern Italy: actual peak temperatures of 41°C will be reached in Tuscany and Emilia, whilst along the Ligurian coast the combination of high temperatures and extreme humidity will cause the perceived temperature to soar to 45°C. To see the light at the end of this Saharan tunnel, we will have to wait until the start of next month. The first few days of July could, in fact, coincide with the Caronte high-pressure system shifting south-eastwards, a movement capable of unblocking the atmospheric circulation and finally allowing cooler, more unstable air currents from Northern Europe to move in. It seems paradoxical given the time of year, but in July, we will most likely be more comfortable than we are now.