Portugal will be affected, on Friday and Saturday (November 18 and 19), by a cooler mass of air with a maritime polar origin, according to BestWeather PT.

In Lisbon, for example, it is expected that the thermometers will not exceed 16ºC, with the minimum going down to 11ºC. In Porto, it will be a little cooler, with expected minimums of 9ºC and maximums of 14ºC.

The coldest regions will be Guarda, with minimum temperatures of 2ºC, Vila Real and Viseu, of 3ºC, and Bragança, of 5ºC.

In the Algarve, the weather will be warmer, with highs reaching 18ºC. In the Alentejo, the cold will also be felt, with forecasts of 15ºC of maximum and 7ºC of minimum for Évora.

This cooler air mass, according to Best Weather PT, can potentially bring with it some showers and thunderstorms, “fed by the thermal differences between the still very warm sea and the cold at height”, with the site predicting that above 1,400 metres there will be a chance of snow.

On Sunday it will rain heavily and temperatures will rise again, with the arrival of stuffy, humid air from the tropical regions.