The districts of Viana do Castelo, Braga, Porto, Aveiro, Coimbra, Leiria, Lisbon, Setúbal, Beja and Faro are under yellow warning until 00:00 on Wednesday due to the forecast of strong wind from the north quadrant, with gusts up to 70 kilometres per hour (km/h) on the coast.
The Portuguese Institute of the Sea and the Atmosphere (IPMA) also placed the Madeira archipelago under a yellow warning until 18:00 today because of the strong northeasterly wind, with gusts up to 75 km/h.
Also under yellow warning are the districts of Aveiro, Coimbra, Leiria, Lisbon, Setúbal, Beja and Faro because of the sea turmoil, with northwest waves 4 to 5 metres high.
This swell warning will be in effect between 12:00pm today and 3:00pm on Wednesday.
Mainland Portugal has registered a change in the weather since Monday with an increase in cloudiness, a gradual drop in temperature, and strong winds on the west coast and in the highlands until Wednesday.
Sharp drop in temperature
The IPMA forecast also points to a sharp drop in temperatures until Friday, especially the maximum, in the order of 10 to 15 degrees Celsius in some places over the weekend.
"Thus, temperatures will go from above average to values significantly below average," the institute said in a statement.
Maximum temperatures should not exceed 12 to 15 degrees in most of the territory, being slightly higher on the south coast of the Algarve, and below 12 degrees in the North and Central interior.
With regard to minimum temperatures, values between 0 and 4 degrees are expected in the North and Centre interior, where ice and frost may form.