These mists and fogs will probably be denser and extra persistent within the depressions of the northeast of the peninsula, the inside of Lugo, the center valleys of the Tagus and Guadiana, and, particularly, the Northern Plateau. Read
https://www.elmundo.es/espana/2024/12/27/676e5731e4d4d8dc378b4575.html
Dense and chronic fog retains 14 provinces on alert whereas the solar reigns in most of Spain | EUROtoday
