The cold snap is expected to last into Thursday, according to the national weather service AEMET.
As the Azores anti-cyclone retreats, a powerful mass of continental cold air will enter the peninsula from the northeast on Tuesday and advance over the entire territory. Temperatures could plunge below -10ºC in parts of Spain, and -15ºC in mountain areas of the Pyrenees and Iberian System.
Wednesday is being forecast as the coldest day of the week, with highs of no more than 5ºC across much of the peninsula.
Authorities have issued a weather advisory in 22 provinces, and warned about the possibility of avalanches in northwestern mountain areas, particularly Huesca, Lleida, Girona and Navarre – where residents of mountain villages have already spent the weekend shoveling snow from their front lanes and cars.
More snow may be seen in the coming days at altitudes as low as 500 meters above sea level in the Pyrenees and the Balearic Islands.
Madrid, Barcelona, Alicante, Valencia, Mallorca and Menorca are on alert for strong winds that could gust up to 80 km/h, and coastal areas have been warned about dangerous sea conditions.
English version by Susana Urra.