The Alaska cruise season runs from late April through early October, with each period offering its own highlights. May and September—the “shoulder seasons”—are excellent for travelers seeking lower prices, fewer crowds, and strong wildlife-viewing opportunities as animals emerge from hibernation or prepare for winter movements. June through August marks the peak season, featuring the warmest temperatures, longest daylight hours, and abundant wildlife activity—think salmon runs, glacier calving, whales, and bear viewing—but expect higher prices and busier ports.