The districts of Castelo Branco, Portalegre, Santarém, Lisbon, Setúbal, Évora and Beja will be under yellow warning between 12:00 on Friday and 15:00 on Saturday due to the persistence of high values of the maximum temperature.
The IPMA had already said that in the next few days yellow hot weather warnings would be issued in some districts.
According to the institute, as of today, an "anticyclone west of the mainland, which extends across a mountain range to the Bay of Biscay" will intensify.
IPMA explains that this situation leads to the transport of a dry tropical air mass from the interior of the Iberian Peninsula.
Therefore, as of 8 July and until 10 July, a gradual rise in temperature values is expected, especially in the maximum.
The values of the maximum temperature, which have been successively below the average for the time of year (except in the Algarve), will gradually rise to values above the average in the majority of the territory.
On Saturday, the maximum temperature values should vary approximately between 33 and 38 degrees Celsius, with the exception of the western coastal strip, where they should be lower and vary between 24 and 30 degrees, and in some places in the interior of Alentejo and the Vale do Tejo, where values of 40 degrees can be reached.
According to IPMA, this episode will be temporary, since on Sunday and Monday, with the entry of sea air, there will be a gradual decrease in the maximum temperature, extending from the coast to the interior.
“It should also be noted that the nights will be cool in most of the territory, although in some places in the interior of the Center and South, particularly in the highlands and in the Algarve, tropical nights are expected”, is mentioned in the note.
The IPMA also indicates that on the western coastal strip the wind will blow from the north-northwest, more intense from the afternoon onwards.