The heat will be less extreme the last weekend of May

BarcelonaThe historic heatwave we've been experiencing for days peaked this Friday in the southern interior of the country. Of note are the 39.5 °C recorded in Vinebre (Ribera d'Ebre). This is the highest maximum ever reached in a May in all of Catalonia, shattering the absolute record in force until now: the 38 °C registered in May 2022 in Castellbisbal (Vallès Occidental) and Anglès (Selva). This historic data joins the large number of records that have fallen between Thursday and Friday throughout the country (you will find the most outstanding data from this historic heatwave at the end of this information).

On the other hand, thermometers did not rise as much as on Thursday in the regions of Girona and Barcelona, although the heat continued to be intense. The thermal decrease will become generalized and will intensify this Saturday, with less extreme heat. Nevertheless, the atmosphere will remain in full summer with values still between 5 and 10 above the average for the season in many cases this last weekend of May. All this with sunshine in general, but with irregular and locally strong showers and thunderstorms that will gain ground in the afternoons in the Pyrenees and Pre-Pyrenees. Throughout next week, it seems that the mercury will gradually decrease and the heat will be much more bearable.

Saturday: temperature drops

The thermal decrease that began in some regions on Friday will continue this Saturday. The night has once again been tropical in spots, especially along the coast, pre-coast, and south of the country, but maximums will generally decrease and the heat will no longer be so extreme.

However, the atypical mid-summer atmosphere will be maintained, and there will be values clearly above average. Many maximums of 30 to 35 ºC are expected inland, but up to 36 or 37 ºC in Ponent and the southern interior. On the coast, there will be readings of 26 to 30 ºC, with marked mugginess.

All in all with sun in general, without ruling out some low coastal cloud in the early morning. In the afternoon, clouds will grow stronger in the Pyrenees, Pre-Pyrenees and the interior of the Valencian Community, where showers and thunderstorms will increase. They will fall irregularly in these areas, and since we are coming from so much accumulated heat, some local downpour accompanied by hail or sleet is not ruled out. Where it rains, the cooling will be sudden. Towards the evening, the remains of scattered clouds will arrive in other regions.

Sunday: heat and afternoon showers

Sunday's temperatures will remain very high for the season –the last day of May– and will even rise again temporarily in some regions, especially in the south of the country. Therefore, the very intense heat and heatwave conditions will continue, with many values above 30 ºC. In Ponent and the interior of the Ebro, maximums of 36 to 39 ºC will be recorded again.

All this with weather very similar to Saturday's. Therefore, radiant sun will generally dominate, and in the afternoon powerful clouds will grow again in the Pyrenees, Pre-Pyrenees, in the interior of the Valencian Community, and surely in the Ports. In these areas, irregular and locally strong showers and thunderstorms are expected. Between the evening and the night, intervals of clouds will reach the coast, as a result of the remnants of these clouds.

Pending a possible refresh

Maps indicate that throughout next week temperatures will continue to drop and approach thermal normalization for the season. A situation still uncertain that we will have to keep confirming, but which would make us breathe much better, coinciding with the beginning of June. Tuesday could bring a spell of showers and thunderstorms in more regions outside the Pyrenees and Pre-Pyrenees.

Balance of a historic heatwave

The long, historic, and premature heatwave we are experiencing these days in Catalonia and much of Europe is the result of a powerful anticyclone that is causing what is known as the heat dome effect: the air does not circulate and we have strong solar radiation that heats the atmosphere considerably, causing heat to accumulate and become more intense day after day. An episode that has left many heat records in our country and across the continent. The most notable figure is the 39.5 ºC reached on Friday in Vinebre (Ribera d'Ebre), which has become the new absolute heat record for the month of May in all of Catalonia. But there have been exceptional figures for the time of year throughout the territory. Also noteworthy are the 37.5 ºC reached at the Lleida station on Friday, which, with 86 years of data, has recorded its May heat record, surpassing the record set the previous day. There have been several records in Ponent and Ebre, where it was hottest on Friday.

Friday in the early morning, the weather has been tropical in many parts of the coast and especially the pre-coastal areas. Torrid lows have even been recorded, above 25 °C. This is the case of the Fabra Observatory in Barcelona, where the 25.3 °C minimum recorded on Friday morning is the new provisional record for nighttime heat in a May in 112 years of data, but finally in the evening the thermometer dropped below this mark and, technically, it ceased to be a record for a full day. Also noteworthy are the 25.7 °C minimum in Portbou (Alt Empordà), where on Thursday the temperature did not drop below 28 °C, the new record for the highest minimum in May in Catalonia. An extraordinary event very localized in this area due to the reheated tramuntana that blew there.

We have experienced the worst two days of this historic and premature heatwave, which on Thursday set many heat records for the month of May. The centennial Ebre Observatory also broke its own May record, with 37.3 °C. The city of Girona reached 37 °C in May for the first time since records began, and the Raval neighborhood of Barcelona also broke its own May heat record, with a maximum of 33.6 °C. Many other municipalities also reached their own heat records on Thursday.