Between late January and March, drift ice from the Sea of Okhotsk pushes in against the Shiretoko coast, turning the shore into a surreal frozen seascape. This is the world's southernmost drift ice, a natural phenomenon unique in Japan, and it transforms the peninsula's character completely. The ice can be several metres thick and extends kilometres offshore; at its peak it is solid enough to walk on.
Ice-breaking cruise ships operating from Utoro and nearby Abashiri offer the best way to experience the drift ice from close range. On these cruises you are likely to see Steller's sea eagles — enormous birds with four-metre wingspans — perched on ice floes waiting for fish, alongside smaller white-tailed eagles and sea ducks. Red foxes sometimes walk directly on the ice. The Shiretoko World Heritage Centre in Utoro has good exhibits on the drift ice ecosystem for those who want context.