When Does Blackduck Lake Freeze? Typical Ice-In Nov 25, Ice-Out Apr 18
Blackduck Lake in St. Louis County, Minnesota usually freezes over around Nov 25, and usually has ice-out around Apr 18, based on Minnesota DNR ice observations recorded between 2012-2022. That works out to roughly 221 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 Blackduck Lake
| Typical freeze-up (ice-in) | Nov 25 |
| Typical ice-out | Apr 18 |
| Earliest freeze-up on record | Nov 11, 2019 |
| Latest freeze-up on record | Dec 13, 2016 |
| Earliest ice-out on record | Mar 19, 2012 |
| Latest ice-out on record | May 10, 2022 |
| Open-water season | ~221 days |
| Winters observed | 20 |
| Location | St. Louis County, Minnesota |
These are dates, not an ice-safety reading
A typical freeze-up date tells you when Blackduck 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 Blackduck Lake has landed as early as Mar 19, 2012 and as late as May 10, 2022 — a spread of weeks around the Apr 18 median. Freeze-up has ranged from Nov 11, 2019 to Dec 13, 2016. 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. Blackduck Lake carries an overall water-quality grade of C — the full breakdown is on the lake report.
Source: Minnesota DNR Climate Office ice-in / ice-out records, observations from 2012-2022.