Tools / Ice-out explorer
When does the ice usually go out on your lake?
Pick one of 65 Minnesota lakes with long records. See its median ice-out date, how much it swings, whether it has moved over the decades, and how often ice was gone by the date you are planning around.
65 lakes with long records. Median, range and chances use 1950 to 2026 (77 years). Earliest and latest cover the full record, which starts in 1855.
April 12
Southern Minnesota · 77 years
Minnetonka
- Median ice-out
- April 12
- Middle 80 percent
- Mar 30 to Apr 24
- Earliest on record
- Mar 11, 1878
- Latest on record
- May 5, 1857
Was the ice usually out by April 12?
In about 51% of the years in this lake's record, ice was out by April 12.
Counting only 2000 to 2026 (27 years), the figure is about 63%.
The past does not promise this year. Weather in March and April decides each spring. This is how often ice has gone out by a date in past records, not a forecast and not a guarantee for any lake.
Has it moved over the decades?
1.7 days earlier per decade
The 95 percent range (−2.7 to −0.6 days per decade) stays on one side of zero, so this lake's record does show a drift toward earlier ice-out. It does not say why.
Ice-out dates are not an ice safety tool
They say when ice has usually gone. They say nothing about whether the ice on a given day is safe. No ice is safe, and thickness can differ across one lake and change within a day. Read the DNR's ice thickness guidelines and our guide to what they leave out. If you are unsure, stay off.
How to read this
What a percentage means
"About 40 percent" means ice was out by that date in roughly 4 of every 10 years in the lake's record. It is a count of past springs. It is not a forecast for this year.
What a trend line can and cannot say
The trend is a straight line through the lake's own years, with a 95 percent range. When that range includes zero, the record cannot tell a shift from ordinary swings. Nothing on this page says what caused a change.
Why two numbers
The whole-record figure uses every year. The since-2000 figure uses only recent years and is shown where a lake has at least 10 of them. When they differ, recent springs have behaved differently from the long run, though a short record is noisy.
Not safety advice
Ice-out is not a measure of safe ice. Use the DNR's ice safety guidance and the thickness guide.
The statewide findings, county by county and by decade, are in our ice-out research. To see how often ice was still on at the fishing opener, read Will your lake be open on the fishing opener?
How this was made
Primary sources (3)
- State agencyMinnesota DNR: ice-out dates reported by volunteer observers
- State agencyMinnesota DNR: data and software license
- State agencyMinnesota DNR: ice thickness guidelines
- Date checked
- Sources opened and read on . Rules and prices change; confirm with the source before you act.
- Method
- For each lake we keep one ice-out date per year, then compute a median, the dates that mark each tenth of its years, a straight-line trend with a 95 percent range, and the same figures since 2000. The chance of ice being out by a date comes from those summary dates. Only these summaries are published. No individual DNR report is reproduced.
- Review status
- Draft AI research draft, human review pending. No named person has reviewed this page, and nobody from MNIRL has checked it in person. What our labels mean.
What we do not know
- Whether a lake's ice-out is recorded the same way every year. Observers and definitions can change.
- Whether the DNR data license clears what we publish. Our plain reading is that derivative works are allowed and the full data may not be redistributed, so we publish only summaries. We have not asked the DNR.
- How each observer defined ice-out. The DNR does not say.
- Anything about this year. Weather decides each spring.
Found a mistake?
Email rice.john.nextgenai@gmail.com with the page and a source. We review each one and note corrections on the page.