Tracking Lake Winnipesaukee’s Ice-Out History & Predictions

For many in the Lakes Region, “ice-out” on Lake Winnipesaukee—when the lake is first fully navigable in spring—holds as much intrigue as the first freeze in fall. It’s a milestone that’s been tracked for over a century, and December brings subtle clues that hint at the coming thaw.

A Look at History

The official ice-out record on Winnipesaukee dates back to 1851. Over the decades, the timing has shifted: early dates in March, later ones into May.

The pattern of those dates often reflects larger trends in winter and spring temperatures, ice thickness, and snow cover.

Why December Matters

While ice-out is months away in December, several early indicators begin shaping the outcome:

• Early snow or freezing days can contribute to thicker ice.
• Warm spells or rain may erode newly forming ice or delay solidification.
• Lake water level – the state of the dam and winter inflows can influence how the ice forms or breaks later.
• Historical analogs – comparing similar winters from past decades gives forecasters reference points.

What Experts Watch

Local observers sometimes track “first freeze” dates, snow depth, and early ice build. In January and February, these observations feed into predictions for when the Mount Washington (the steamer) can resume navigation across ports like Center Harbor, Weirs, Meredith, and Alton.

If you’re a lake enthusiast, keeping an eye on December and January weather—especially cold spells and snow accumulation—can offer hints about that year’s ice-out rhythm. And next April or May, when the lake finally clears, you’ll have a richer sense of how winter shaped the thaw.