Temperate climates (Köppen C and D groups) have warm summers and cool winters with distinct seasons. Oceanic (Cfb: London, Paris) stays mild year-round; continental (Dfb: Warsaw, Chicago) has extremes. Fashion versatility is highest in temperate climates: layering systems replace single-fabric solutions. Merino wool is the canonical temperate fabric (regulates from 5°C to 25°C). Lightweight wool, cotton, and linen work spring through autumn.