September begins with very high temperatures in mainland Portugal. From Wednesday, maximum temperatures will rise between 10 to 12 degrees Celsius in some locations, potentially reaching 40 to 42 degrees in the Tagus Valley, Beira Baixa and Alentejo, according to the Portuguese Sea and Atmosphere Institute (IPMA). On Thursday, the maximum temperature will be between 34 and 38 degrees across most of the territory, while values of 40 to 42 degrees are expected in the inland regions south of the Serra da Estrela mountain range.
IPMA meteorologist Maria João Frada told the Lus news agency that the rise will be gradual but sharp, with the southern coast of the Algarve seeing less significant increases, between 5 to 6 degrees. The minimum temperature should also rise sharply in the central and southern regions, but only on Thursday. By Friday, a drop in temperature is already expected on the coast and in the western half of the territory, although it will not drop as much as it rose in the previous days.
According to the specialist, this temperature rise is due to an anticyclone positioned roughly northeast of the Azores or northwest of mainland Portugal, which extends toward Central Europe. This anticyclone, together with a depression trough extending from North Africa to the Iberian Peninsula, causes the transport of a warm air mass from the Iberian Peninsula or North Africa. It is likely that on Thursday there will be dust from North Africa in the southernmost regions of the country. No precipitation is forecast, although until Tuesday there will be some temporary cloud cover.
