When Does Steamboat Bay Lake Freeze? Typical Ice-In Dec 1, Ice-Out Apr 28
Steamboat Bay Lake in Cass County, Minnesota usually freezes over around Dec 1, and usually has ice-out around Apr 28, based on Minnesota DNR ice observations recorded between 1950-2018. That works out to roughly 217 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 Steamboat Bay Lake
| Typical freeze-up (ice-in) | Dec 1 |
| Typical ice-out | Apr 28 |
| Earliest freeze-up on record | Nov 20, 2018 |
| Latest freeze-up on record | Dec 17, 1998 |
| Earliest ice-out on record | Apr 2, 2012 |
| Latest ice-out on record | May 23, 1950 |
| Open-water season | ~217 days |
| Winters observed | 231 |
| Location | Cass County, Minnesota |
These are dates, not an ice-safety reading
A typical freeze-up date tells you when Steamboat Bay 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 Steamboat Bay Lake has landed as early as Apr 2, 2012 and as late as May 23, 1950 — a spread of weeks around the Apr 28 median. Freeze-up has ranged from Nov 20, 2018 to Dec 17, 1998. 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. Steamboat Bay Lake carries an overall water-quality grade of B — the full breakdown is on the lake report.
Source: Minnesota DNR Climate Office ice-in / ice-out records, observations from 1950-2018.