Duluth, Minn. — Minnesota Sea Grant launched an enhanced version of the Minnesota Lakes Ice-Out Clock for 2025 in early February that makes it easier than ever for Minnesotans to estimate when their favorite lakes will be free of ice.
"This year’s update includes a new lake search feature that allows users to quickly look up forecasts for specific lakes across Minnesota," said John Downing, Minnesota Sea Grant director and project leader. "We anticipate that seasonal businesses and outdoor enthusiasts will find value in our ice-out forecasting tool."
The Minnesota Lakes Ice-Out Clock uses the latest National Weather Service weather data, lake size, latitude, and seasonal snowfall trends to provide estimates of when ice will likely leave the lakes. Forecasts are now available starting January 1, which gives users the ability to track how conditions change throughout the season.
How It Works
To get an estimated ice-out forecast, users simply select a county and choose a lake. Each forecast provides three possible ice-out dates based on low, average, and high seasonal snowfall. Since the final snowfall total for the season is unknown until winter ends, users must guess at this season's snowfall. To do that they can compare their region’s past snowfalls using tools like the Minnesota Department of Natural Resources Weekly Snow Depth and Rank Maps and the National Weather Service snowfall data.

Understanding Ice-Out Forecasts
Sea Grant's Minnesota Lakes Ice-Out Clock is based on more than 15,000 historical ice-out records and data on lake location, latitude, and size from the Minnesota Department of Natural Resources (MNDNR) and weather data from the National Weather Service (NWS). It accounts for key factors such as:
- Total seasonal snowfall, which influences ice thickness and duration.
- Degree Days, which are a measure of freezing and thawing intensity.
- Lake size and the north-south location of the lake.
- Historical ice-out trends from lakes across the state.
While the forecasts provide an estimate of when lakes will be ice-free, they do not indicate when ice is safe. Ice conditions can and do change rapidly, and safety is the responsibility of each individual.
Why Snowfall Matters
Snowfall plays a critical role in prolonging ice cover because it contributes to “snow ice” formation and thickening lake ice. It also reflects sunlight, which slows ice melt and insulates the lake surface, which prevents rapid thawing.
Improved Accuracy Over Time
The Minnesota Lakes Ice-Out Clock forecasts become more accurate as winter progresses. Late-winter predictions tend to be closer to actual ice-out dates than early-season forecasts, which rely more heavily on freezing patterns and snowfall trends.
Tourism
Among the most important problems faced by the tourism industry is seasonality, including the start and end dates of the high season as well as the duration of peak use. Variation in seasonality and a lack of means by which to forecast the timing of recreation seasons are among the most economically impactful pressures on the tourism industry.
Tools like Minnesota Sea Grant's Minnesota Lakes Ice-Out Clock can help businesses forecast the timing and duration of tourism seasons, and potentially save them time and money in the operation of their businesses.
"Because Minnesota’s economy and well-being is deeply tied to its lakes, ice-out forecasting plays a major role in helping businesses maximize their sometimes short operating windows and helps people seeking outdoor recreation opportunities adapt to changing weather outcomes," said Downing.
CONTACTS:
John Downing, Director, Minnesota Sea Grant, University of Minnesota and University of Minnesota Duluth, [email protected].
Marie Thoms, Communications Manager, Minnesota Sea Grant, University of Minnesota and University of Minnesota Duluth, [email protected].