Storm Filomena was an extratropical cyclone in early January 2021 that was most notable for bringing unusually heavy snowfall to parts of Spain, with Madrid recording its heaviest snowfall in over a century, and with Portugal being hit less severely. The eighth named storm of the 2020–21 European windstorm season, Filomena formed over the Atlantic Ocean close to the Canary Islands on 7 January, subsequently taking a slow track north-eastwards towards the Iberian Peninsula and then eastwards across the Mediterranean Sea.

Madrid is the capital and most populous city of Spain. The city has almost 3.4 million inhabitants and a metropolitan area population of approximately 7 million. It is the second-largest city in the European Union (EU), and its monocentric metropolitan area is the second-largest in the EU. The municipality covers 604.3 km2 (233.3 sq mi) geographical area. Madrid lies on the River Manzanares in the central part of the Iberian Peninsula at about 650 meters above mean sea level. The capital city of both Spain and the surrounding autonomous community of Madrid, it is also the political, economic, and cultural centre of the country. The climate of Madrid features hot summers and cool winters.