Lake Winnipesaukee freeze shows the lake fully covered in ice, marking the typical onset of winter when the lake begins to solidify.
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Lake Winnipesaukee Freeze lake view
Lake Freeze Profile

Does Lake Winnipesaukee Freeze? Ice-In Variability and Earlier Ice-Out

The Broads often freeze last, while the spring ice-out record has shifted earlier over the past 50 years.

Freeze PatternVariable Full/Partial FreezeFreeze-UpTraditional ice-in calls vary from January into early FebruaryIce-OffHistorically mid- to late April; 2026 ice-out was April 12Full FreezeVariable; the Broads can remain open after bays and ports have frozenLocationNew Hampshire, United States
Freeze Signature

Seasonal ice cover with variable whole-lake closure

Long-term climate analysis and observed lake-ice reportingNew Hampshire Climate Assessment 2021 — University of New HampshireNew Hampshire Public Radio — Lake Winnipesaukee Ice-Out 2026New Hampshire Public Radio — Earliest Lake Winnipesaukee Ice-OutNew Hampshire Public Radio — Open Water on Lake WinnipesaukeeWMUR — Lake Winnipesaukee Ice-In 2026Evidence: Moderate
Ice Cover TypeExtensive Seasonal Ice
Primary DriverWind and Mixing
Observed TrendFrom 1971–2020, ice-out shifted about 8 days earlier, with a reported trend of 1.5 days earlier per decade
Why It Freezes This Way

The exposed Broads are typically last to freeze. Wind and lake currents can keep water moving and disrupt new ice even during prolonged cold spells.

Ice conditions are not a safety rating.Freeze dates and ice-cover records do not determine whether lake ice is safe for walking, skating, vehicles, or other activity.
Interactive Lake Map

Where Is Lake Winnipesaukee?

New Hampshire · United States

43.5989° N · 71.3225° W
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Lake WinnipesaukeeNew Hampshire · United States
World View

Lake Winnipesaukee on the Globe

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Lake Winnipesaukee
Measurements

Measured Ice and Freeze Data

USGS Historical Ice-Out Record, 1887–2008122yearsHistorical Monitoring RecordUSGS Historical Ice-Out Dates for 29 Lakes in New England, 1807–2008Evidence: High
Ice-Out Shift, 1971–20208days earlierUniversity Climate AssessmentNew Hampshire Climate Assessment 2021 — University of New HampshireEvidence: High
Ice-Out Trend, 1971–20201.5days earlier per decadeUniversity Climate AssessmentNew Hampshire Climate Assessment 2021 — University of New HampshireEvidence: High
Earliest Recorded Ice-Out Through 2026March 17, 2024Observed Ice-Out RecordNew Hampshire Public Radio — Lake Winnipesaukee Ice-Out 2026New Hampshire Public Radio — Earliest Lake Winnipesaukee Ice-OutEvidence: High
2026 Ice-OutApril 12, 2026Aerial Ice-Out ObservationEmerson Aviation — Ice Out on Lake WinnipesaukeeNew Hampshire Public Radio — Lake Winnipesaukee Ice-Out 2026Evidence: High
Ice Year

Freeze and Ice Cover Through the Year

JANPrimary Ice-In Window
FEBWinter Ice Cover and Late Ice-In Years
MARLate-Winter Ice and Possible Early Breakup
APRPrimary Ice-Out Month
MAYTypical Open-Water Period
JUNTypical Open-Water Period
JULTypical Open-Water Period
AUGTypical Open-Water Period
SEPTypical Open-Water Period
OCTTypical Open-Water Period
NOVTypical Open-Water Period
DECPre-Ice-In Transition

Month-level states are shown only when supported. Unclassified months remain explicitly marked.

Evidence

Evidence Behind the Freeze Profile

The Broads can be the last major area to freeze

A 2014 aerial observation found substantial open water in the Broads after prolonged cold, while a New Hampshire Fish and Game lake biologist cited wind and current as obstacles to ice formation there.

Observed Lake ConditionsNew Hampshire Public Radio — Open Water on Lake WinnipesaukeeEvidence: Moderate
References

Sources

Lake Winnipesaukee develops extensive winter ice, but freezing is not uniform across the lake. Sheltered bays and port areas can close while open water persists in the Broads, so a traditional ice-in declaration should not be treated as proof that every part of the lake has continuous ice cover.

Why the Broads can remain open after other areas freeze

The Broads are one of the clearest reasons Lake Winnipesaukee does not behave like a small, sheltered pond. This exposed central part of the lake is commonly among the last sectors to lock up. Wind can keep the surface moving, break thin new ice and mix water beneath it. Lake currents add another source of motion.

A winter in 2014 showed the difference plainly. After extended cold spells, an aerial survey still found a large area of open water and questionable ice stretching through the Broads from the Gilford side toward Moultonborough. A New Hampshire Fish and Game large-lake biologist noted that cold temperatures alone were not enough: calm conditions were also needed for the surface to catch and remain frozen. He also pointed to current flow as another factor working against ice formation that season.

This spatial difference matters when describing Winnipesaukee as frozen. Ice in a bay, harbor or shoreline zone does not establish the condition of the exposed central lake.

What an ice-in call means on Winnipesaukee

The lake’s traditional ice-in designation is tied to the five ports visited by the M/S Mount Washington. Recent declarations have moved between January and early February, reflecting how strongly each winter’s sequence of cold, wind, rain and thaw can alter the timing.

The 2024 season showed how temporary that threshold can be. Ice-in was declared on February 9 after an unusually slow freeze, yet melting reportedly began only about a day later. That episode is better read as an example of winter-to-winter variability than as a normal freeze duration.

For the same reason, ice-in is not a lake-wide ice-cover percentage. A port-based declaration, a frozen sheltered bay and complete closure of the Broads describe different conditions and should remain separate.

Ice-out can be called while isolated ice remains

Lake Winnipesaukee has one of New England’s longest-known ice-out traditions. The modern call is made from aerial observations when the M/S Mount Washington could navigate to Alton Bay, Center Harbor, Meredith, Weirs Beach and Wolfeboro without winter ice blocking its route.

That definition does not require the entire surface to be completely free of ice. When ice-out was declared on April 12, 2026, ice still remained in places including Moultonborough Back Bay and Winter Harbor. Those remnants did not obstruct the vessel’s route, so the navigation threshold had already been reached.

This distinction is useful when comparing ice-out dates with satellite ice-cover measurements or photographs from a single bay. They may be describing different stages of breakup even when all observations are correct.

The spring thaw record is moving earlier

The U.S. Geological Survey compiled 122 years of Lake Winnipesaukee ice-out dates from 1887 through 2008. The historical definition was not perfectly identical across every observer and every year, although for most of the record it was associated with open navigation for the M/S Mount Washington.

A later University of New Hampshire climate assessment examined the long record through 2020 and found a clear directional change. From 1971 through 2020, Lake Winnipesaukee ice-out shifted about eight days earlier. The reported trend over those five decades was 1.5 days earlier per decade.

Year-to-year weather still produces wide variation. An early spring does not guarantee that the following year will break another record. The longer record is more informative: March 17, 2024 became the earliest recorded ice-out, while the 2026 declaration returned to April 12. The trend describes a change in the distribution of spring breakup dates, not a steady move toward an earlier date every single year.

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