Minnesota's thinning ice raises safety alarms as spring temperatures climb

Warmer spring temperatures have thinned ice on Minnesota's lakes and rivers by up to 20% over the past five years. Officials now warn that rising mercury levels are making frozen surfaces less predictable. The state's Department of Natural Resources (DNR) is urging extra caution for anyone venturing onto the ice this season.

Data from the Minnesota DNR and NOAA shows a clear trend: average ice thickness in March and April has dropped by 15–20% since 2021. The decline stems from higher spring temperatures and earlier thawing. Areas near shores and access points may be even weaker due to salt runoff and decaying vegetation.

The DNR recommends checking ice thickness regularly once temperatures climb into the 40s and 50s. A simple ice chisel is the best tool for the job. Clear, blue ice needs to be at least 4 inches thick to support foot traffic safely, while cloudy or milky ice requires double that—8 inches—before it can be trusted.

Authorities stress that no ice is entirely risk-free. Conditions can change rapidly, especially as the season warms. Anglers, skaters, and snowmobilers are advised to stay vigilant and avoid unfamiliar areas without proper testing.

The thinning ice poses real risks for outdoor activities in Minnesota. With temperatures continuing to rise, the DNR's guidelines on thickness checks and tool use aim to prevent accidents. Residents and visitors are being reminded to prioritise safety before stepping onto frozen water.