The districts of Bragança, Viseu, Porto, Vila Real, Viana do Castelo, and Braga will be under a yellow warning between 11 am and 9 pm on 25 May, according to the Portuguese Institute of the Sea and the Atmosphere (IPMA).

The institute forecasts hot weather on the mainland for the same day, with the possibility of showers and thunderstorms in the north and centre during the afternoon, sometimes strong winds in the highlands, fog on the north and central coast, and a slight rise in temperature.