Lisbon, Aug. 20, 2026 (Lusa) - Mainland Portugal may experience a low-pressure system on Sunday with «characteristics that are unusual for this time of year», which could bring persistent rain, strong winds and rough seas, a source at the IPMA told the Lusa news agency on Thursday.

Speaking to the Lusa news agency, Ângela Lourenço, a meteorologist at the national meteorological institute, IPMA, said that the low-pressure system, which is expected to pass north of the Azores before reaching mainland Portugal, could make itself felt as early as late on Saturday, depending on its speed, although the most likely scenario suggests its effects will only be felt on Sunday.

«This low-pressure system, which brings associated frontal systems, will affect us at the start of next week and has some characteristics more typical of autumn. Sometimes, in summer, there are frontal disturbances that deviate slightly from their normal trajectory,» she explained.

Lourenço noted that the IPMA is assessing and monitoring the situation to determine whether the low-pressure system will indeed arrive on Sunday and, if so, under what conditions.

«On its path from the Azores until it reaches us [the mainland], there may be some disturbances here that cause it to take on different characteristics. We will monitor it and see what its key features are in terms of weather conditions or the impact it may have,» she noted.

According to the meteorologist, the general forecast points to a change in weather conditions, with rainfall from Sunday and throughout much of the following week, «which may at times be heavy».

«At the moment, everything suggests that, if it is more intense, it will affect the northern and central regions more than the south, but we'll have to wait and see,» she said.

Ângela Lourenço added that the situation could bring periods of stronger winds and rougher seas, these being the main impacts associated with the passage of the low-pressure system.

As for temperatures, she noted that the most significant drop occurred on Wednesday and is expected to continue today, albeit «less sharply», with temperatures set to remain stable over the coming days.

«There may be slight rises in some places tomorrow [Friday] and on Saturday, [whilst] in others temperatures will remain the same,» she emphasised.

On Tuesday, the IPMA placed the districts of Viana do Castelo, Braga, Porto, Vila Real, Bragança, Aveiro, Viseu, Guarda and Coimbra under an amber warning due to the forecast of hot weather.

FAC/ADB // ADB.

Lusa