Portugal has a predominantly Mediterranean climate (Köppen Csa/Csb) with hot dry summers and mild wet winters, heavily influenced by Atlantic currents, averaging 2,500-3,200 sunshine hours annually — one of Europe's sunniest regions. The northern Atlantic zone (Minho) is cooler and wetter with substantial winter rainfall; the central interior has continental extremes (winter frost in the Serra da Estrela, summer heat regularly exceeding 40°C); the south and Algarve are semi-arid to stable Mediterranean, with mild short winters and long hot summers moderated by coastal breezes. Prolonged summer droughts place central/northern forested interior zones under high wildfire alert from June-September; property owners must clear dry brush within 50 meters of residential buildings by April 30 annually. Older mid-century apartment blocks generally lack central insulation, requiring dehumidifiers in winter and AC/heat pumps in summer.