While 2005 will not go into the record books as the earliest ice-out ever for any Minnesota lakes with long-term records, the rapid spring warm-up moved the ice out more quickly than what was expected at the beginning of April.

Pete Boulay, assistant state climatologist for the Minnesota Department of Natural Resources (DNR), said conditions changed quickly.

“Prospects for an early ice-out for 2005 didn’t seem to be in the cards for Minnesota,” Boulay said. “The statewide temperature average for March 2005 was just a little cooler than average. Indeed the first few lakes in far south-central Minnesota lost their ice near historical averages.”

Tiny Iowa Lake in Martin County was first, losing its ice by March 28. Budd Lake in Martin County followed on March 30, one day later than the historical average.

Then, however, April arrived with May-like temperatures. The first 17 days of the month were 10 degrees above average statewide. Even in northeastern Minnesota, which held onto a snow pack at the beginning of April, temperatures were seven degrees above average.

“The balmy conditions accelerated ice-out across the rest of Minnesota,” Boulay said.

In central portions of the state, lakes like White Bear and Minnetonka were ice free by April 9, which was several days ahead of average. Green Lake in Kandiohi County lost its icy cover on April 10, six days ahead of its long-term average. In general, lakes were ice free three days to a week ahead of average in Central Minnesota.

“Mille Lacs was stubborn to lose its ice,” Boulay noted. “One couldn’t pilot a boat from Isle to Garrison until April 20, but that was still four days earlier than average.”

The warmth continued during the third week of April and ice thawed on northern lakes more rapidly. As of April 21, virtually all lakes across northeastern Minnesota were ice free.

Even lakes that typically keep their ice the latest, like Vermillion, looked blue to airplane pilots on April 19. The last two years Vermillion was still iced until the end of April. Shagawa Lake, just north of Ely, lost its ice 10 days ahead of average. Most lakes in northern Minnesota were ice free seven to 10 days ahead of average.

By Monday, April 25, all Minnesota lakes were ice free. The last lakes to lose their ice were the Canadian border waters of Rainy Lake and Lake of the Woods, both ice free April 23.