Heat warning issued this weekend, marking first heatwave of summer

The Catalan meteorological agency, Meteocat, has issued a heatwave warning for this weekend, the first one of this year's summer season across Catalonia. This will not only be a heatwave on the ground, but also across the Mediterranean Sea, with warmer water temperatures.

The agency reported on Friday morning that temperatures could surpass 40ºC in western and southern Catalonia from Saturday to Tuesday.

"June will end with a constant and out-of-control heat," Santi Segalà, head of weather forecast at Meteocat, said in a written statement.

Temperatures will be near 40ºC in Ponent, western Catalonia, and Terres de l'Ebre, in the south, and will range between 34ºC and 39ºC across inland Catalonia. Meanwhile, temperatures on the coast will range between 30ºC and 34ºC.

Due to these forecasts, the agency has issued several heat warnings, at least until Tuesday.

Night temperatures will also be quite warm, with lows of 22ºC or 23ºC. In Barcelona, for example, temperatures will be around 25ºC at night, which is considered a tropical night.

Experts forecast a temperature drop from next Wednesday, but temperatures will remain above average. No rain is expected across the territory, but due to the warm weather, there will be some localized storms in the northern areas of Catalonia in the afternoons.

In L'Estartit, in the Costa Brava, water temperature on June 20 was 23.1ºC, as data from analyst Josep Pascual shows. This is 2.6ºC higher than the average registered between 1998 and 2022, which stood at 20.5ºC, and it is similar to temperatures registered in late July, as opposed to late June.

"Sea temperature is far above average for these dates," Segalà said.

Marc Prohom, head of climatology at Meteocat, also added that "sea heatwaves on the Mediterranean are more frequent, last longer, and are more intense due to climate change."

Experts warn that this directly affects marine life and ecosystems such as corals and posidonia, also known as Neptune grass.