"Temperatures will rise sharply starting today in some regions of the mainland, such as the Alentejo and Tagus Valley, to around 5 to 6°C. On Sunday, temperatures will generally be around 30°C in the southern region, the Alentejo and Tagus Valley," meteorologist Patrícia Marques told Lusa.

Minimum temperatures will also rise, potentially reaching 17-18 degrees Celsius, according to a meteorologist at the Portuguese Institute of the Sea and Atmosphere (IPMA).

"These temperatures, above normal for this time of year, are expected to continue at least until mid-week," she said.

For the Madeira archipelago, periods of very cloudy skies are expected, with the possibility of light showers in the highlands starting in the afternoon, and generally light north/northeast winds.

Minimum temperatures are expected to be around 20 degrees Celsius and maximum temperatures around 25-26 degrees Celsius in the Madeira archipelago.

For the Azores archipelago, the IPMA forecasts very cloudy skies for Sunday, with clearings, periods of rain in the early morning, changing to showers, and moderate winds.

Temperatures will be around 19 degrees Celsius and maximum temperatures will be around 24-25 degrees Celsius.

In the municipal elections, which take place between 8:00 a.m. and 7:00 p.m. on Sunday, voters will choose the governing bodies of 308 municipal councils, 308 municipal assemblies, and 3,221 parish assemblies.

Another 37 parishes will choose their executives in citizen plenary sessions, as they have fewer than 150 voters.

According to the Electoral Administration of the General Secretariat of the Ministry of Internal Affairs (MAI), there are 9,303,840 registered voters for the municipal elections.