According to information provided by the Portuguese Institute of the Sea and the Atmosphere (IPMA) on its website, until the 23 December the weather on the mainland will be influenced by an anticyclone located in the interior of the Iberian Peninsula and by a mass of hot and humid air, so periods of heavy cloud cover and some rain are expected, which may be more intense in Minho and Douro Littoral.
Throughout 23 December, a cold frontal surface passing through the North and Center regions will result in light showers, accompanied by a decrease in temperature, to these areas, and then passing through the South, until the early hours of 24 December.
Until the morning of the 24 December, Thursday, there will be mist and fog in some places and the wind will be light to moderate, sometimes strong in the highlands, but during Christmas Eve “a change in the weather is expected, with reduced cloud cover and without precipitation, due to an anticyclone to the northwest of the Iberian Peninsula and a mass of cold and dry air”.
“The temperature will go down, especially the minimums. On the night of the Christmas eve the minimum will be around 2ºC to 6ºC in the north and central coast, 8ºC to 10ºC in the south coast, -2ºC to 2ºC in the north interior and centre, and between 3ºC to 6ºC in the southern interior. The wind will gradually rotate towards the east quadrant, intensifying on 25 December, which, will in turn see a further drop in temperature”, says the IPMA.