When Does Lost Lake Freeze? Typical Ice-In Nov 20, Ice-Out Apr 15
Lost Lake in Cass County, Minnesota usually freezes over around Nov 20, and usually has ice-out around Apr 15, based on Minnesota DNR ice observations recorded between 2007-2017. That works out to roughly 219 days of open water a year. These are typical dates across many winters, not a forecast — individual years swing by weeks in either direction.
Ice record for Lost Lake
| Typical freeze-up (ice-in) | Nov 20 |
| Typical ice-out | Apr 15 |
| Earliest freeze-up on record | Nov 10, 2017 |
| Latest freeze-up on record | Nov 27, 2007 |
| Earliest ice-out on record | Mar 31, 2016 |
| Latest ice-out on record | Apr 30, 2008 |
| Open-water season | ~219 days |
| Winters observed | 20 |
| Location | Cass County, Minnesota |
These are dates, not an ice-safety reading
A typical freeze-up date tells you when Lost Lake has usually iced over — it does not tell you the ice is safe, and we hold no thickness measurement for this or any lake. The Minnesota DNR is explicit that no ice is ever completely safe: thickness varies across a single lake, and current, springs, aerators, and insulating snow all weaken it. Ice that held a truck last week may not hold a person today.
Read the ice-thickness guidelines before going out, and check current conditions with the Minnesota DNR ice-safety page and local bait shops, which track conditions lake by lake.
How much the timing varies
Ice-out on Lost Lake has landed as early as Mar 31, 2016 and as late as Apr 30, 2008 — a spread of weeks around the Apr 15 median. Freeze-up has ranged from Nov 10, 2017 to Nov 27, 2007. That year-to-year swing is why a median date is a planning tool, not a schedule. Freeze-up is driven by accumulated cold after the lake turns over in fall; ice-out by late-winter air temperature, sun angle, and how much snow sits on top of the ice reflecting it. Lost Lake carries an overall water-quality grade of A — the full breakdown is on the lake report.
Source: Minnesota DNR Climate Office ice-in / ice-out records, observations from 2007-2017.