Lake Winnipesaukee Ice-Out occurs when all the ice on Lake Winnipesaukee, the largest lake in New Hampshire, United States, has broken up after winter. Over the years this has been decided upon by a variety of means; as of 2018, Dave Emerson makes the call.[1] Emerson flies two to three times a day over Lake Winnipesaukee to check on the ice. Ice-Out is declared when the MS Mount Washington can make it to every one of its ports: Center Harbor, Wolfeboro, Alton, Weirs Beach and Meredith.[2] It is also considered the unofficial start to the boating season[2] as well as the end of winter[3] in New Hampshire. The earliest recorded ice-out occurred in 2024 on March 17, beating the previous record of March 18, 2016 and March 23, 2012. The latest ice out occurred in 1888 on May 12.[4]
Because the Ice-Out designation is based on the judgment of one person, it is unscientific. The call does not mean that the lake is entirely devoid of ice, nor does it mean that the MS Mount Washington actually does go to each of its ports. It simply means that it is believed that the ship could.[3]