Ice-In & Ice-Out Tracking

Please help Lake Stewards of Maine (LSM) track ice-in and ice-out dates for your lake.

• Submit your observations using our Ice Coverage Submission Form .
• For definitions of ice-in and ice-out, see below.
• For information on partial ice cover, visit Winter Ice Variability .
• View current conditions on the Ice Coverage Map .
• Explore trends in our Statewide Ice Cover Summary .
• Our partners at the Maine Department of Agriculture, Conservation and Forestry (Maine Geological Survey) also provide Snowpack Data . In 2026, peak snow water content occurred around March 4.
• Interested in additional climate-related monitoring opportunities? Learn more about the high-elevation lake monitoring project .

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How do I determine ice-in and ice-out?

LSM tracks when lakes freeze (ice-in) and when they become ice-free (ice-out). While ice-out has historically been recorded, tracking ice duration is increasingly important for understanding changing climate conditions. Ice-out is declared when a lake becomes navigable or mostly ice-free. Methods vary by lake:

• Complete ice disappearance
• Main basin becomes ice-free
• Approx. 80% of ice cover is gone

Important: Always follow the historical method used for your lake when possible. If no record exists, we recommend declaring ice-out when the lake is mostly navigable. Ice-in occurs when a lake becomes fully or nearly fully ice-covered. Because lakes may freeze and thaw multiple times, we track:

• First ice-in event
• Final, sustained ice cover

Note: Skim ice should not be considered ice-in.

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Recommended Methods for Tracking Ice-Out

Consistency is critical. If your lake already has a method, continue using it. If not, consider the following approaches:

1. Use Multiple Observers

Create a small group responsible for observations. This ensures continuity and reduces the chance of missed events.

2. Establish a Photo Station

A photo station provides a fixed viewpoint to document changes over time. This helps create consistent, comparable records year to year. Photo stations can be simple (e.g., a marked post) or more permanent structures. The key is a stable, repeatable view that will not be disturbed. Additional resources:

• Photo Point Monitoring Guide
• US Forest Service – Mountain Views