Minnesota is on track to have its deadliest winter on the ice in years. And it’s only December.

Five people have died after falling through the ice on Minnesota lakes so far this season, the most since five died over the entire winter of 2014-15, according to the Department of Natural Resources.

“With the fluctuating temperatures we’ve seen, that hasn’t created that nice, solid, clear ice,” said DNR spokeswoman Lisa Dugan. “Ice is never 100 percent safe.”

Since 2007, an average of three people have died on the ice every year, with most deaths occurring toward the end of winter rather than the beginning, DNR data shows. Two people died on the ice last winter and none did in 2015-16.

All of this year’s deaths happened on an ATV or snowmobile:

Bernice Elaine Kane of Cohasset died after the ATV she was riding went through the ice on Rice Lake in Itasca County on Saturday evening.

Lauren Lund of Bemidji died after the ATV she was riding broke through the ice on Grace Lake southeast of her hometown early Saturday.

Anthony Bjerkness of Ironton died after his snowmobile went through the ice on Serpent Lake near Crosby on Dec. 11.

Melissa Seidenstricker of Princeton and Zeth Knyphausen of Stacy died on Upper Red Lake after their ATV went through the ice Nov. 27.

There also have been several close calls this season, including a Duluth man who went through the ice with Kane and survived; two men who were rescued Dec. 11 after their snowmobile pulling an ice house went through the ice on St. Mary’s Lake near Eveleth; and a man who was rescue after his snowmobile broke through the ice on Rice Lake north of Duluth on Nov. 26.

“With the warmer wet weather, ice conditions are unpredictable and can vary just short distances apart,” the St. Louis County Sheriff’s Office said following the St. Mary’s Lake rescue.

The deadliest winters this century saw 10 people die on the ice in 2002-03 and eight people die in the winter of 2006-07.

The DNR recommends new, clear ice should be 4 inches thick to walk on, 5 to 7 inches for ATVs and snowmobiles, 8 to 12 inches for cars and 12 to 15 inches for trucks.

“In the past year we increased from 5, to 5 to 7 inches, to take into account the extra weight on side-by-side ATVs,” Dugan said.

White or snow-covered ice should be twice as thick to be considered safe.

Dugan said that other than extreme caution, people should bring with them a chisel and a life jacket or float coat even as temperatures fall below zero this weekend.

“As the conditions start to freeze again, we’re hoping people will take their safety in their own hands. Check the ice not just for thickness but consistency.”