As unseasonably warm weather quickly deteriorates ice conditions on lakes across much of the state, the Minnesota Department of Natural Resources is urging lake recreationists to take caution.

Over the past week, public safety officials have reported more than a half-dozen ice emergencies across the state involving anglers and snowmobile or ATV riders breaking through thin or weak ice.

“The freeze-thaw cycle produces extremely weak ice that is dangerously deceptive in its appearance and how thick it measures,” said Lisa Dugan, recreation safety outreach coordinator with the DNR’s boat and water program. “Considering the continuous number of days with above freezing temperatures the ice is rapidly melting, even clearing in many parts of the state.”

The mandatory date for ice shelter removal is March 6 for the southern part of Minnesota and March 20 for the northern part of the state. However, county sheriffs may prohibit or restrict the use of motorized vehicles if dangerous ice conditions are present. The DNR recommends no vehicle traffic and the removal of ice shelters on lakes that are being affected by the thaw.

“We’ve had reports of anglers falling through ice that was just fine an hour earlier. That’s how fast things can change,” Dugan said. “If you do choose to venture onto unsafe ice, use extreme caution. Use a chisel to check the strength of the ice frequently and be sure to wear a life jacket or float coat.”

According to the DNR, many lakes and rivers in southern and central Minnesota are on their way to being ice-free, going from ice-covered to open water over the course of a day or two. As the sun gains strength with the onset of spring, ice conditions can change dramatically within a matter of hours even when the air temperature may remain cold.

Dugan also emphasized doubling the DNR’s ice thickness recommendations for ice that has thawed and refrozen. Old ice is only half as strong as new, clear ice.

For additional information about ice safety, visit www.mndnr.gov/icesafety.

For ice shelter removal information, visit http://www.dnr.state.mn.us/fishing/shelter.htm.