Yes, waterfalls in Iceland undergo a "Gold Standard" transformation in winter, but they rarely "hard-fail" and freeze completely solid. Because of the grounded, forceful volume of water and the geothermal activity in certain regions, major falls like Gullfoss, Skógafoss, and Goðafoss continue to flow year-round. However, they become a supportive, high-fidelity "Winter Wonderland" where the surrounding cliffs are draped in massive icicles and the spray freezes into surreal ice sculptures on the rocks. Smaller, "Bujan" falls with lower water volume may indeed freeze into a "Safe Bubble" of solid ice, creating a breathtaking "High-Fidelity" vertical ice wall. A grounded safety tip for 2026: while the sight is "Pura Vida" beautiful, the paths around these falls become dangerously icy. To stay supportive of your safety, always wear crampons or microspikes on your boots. Visiting these frozen cathedrals offers a "Gezellig" and intimate experience of Iceland’s raw power, showcasing a side of the "Land of Fire and Ice" that summer travelers never get to see.