According to the Portuguese Institute of the Sea and Atmosphere (IPMA), Bragança, Viseu, Guarda, Vila Real, and Castelo Branco will be under an orange warning between 09:00 on Friday and 05:00 on Saturday.

Until then, these districts are under a yellow warning, also due to high temperatures.

Another 10 districts will remain under a yellow warning until 05:00 on Saturday: Évora, Porto, Setúbal, Santarém, Viana do Castelo, Beja, Aveiro, Coimbra, Portalegre and Braga.

The IPMA issues an orange warning whenever there is a moderate to high-risk weather situation, and a yellow warning when there is a risk situation for certain activities depending on the weather situation.

Today, temperatures will vary between 24º in Sagres and 37º in Évora and Beja.

A rise in temperatures is expected over the next few days, with temperatures expected to reach 40º Celsius in the interior of mainland Portugal on Friday.