TORONTO  —  The winter of 2005-2006 has been Canada's warmest on record, and the federal agency Environment Canada said Monday it was investigating whether it's a sign of global warming.

Between December and February, the country was 3.9 degrees above normal — the warmest winter season since temperatures were first recorded in 1948.

Environment Canada climatologist Bob Whitewood said it smashed the previous record set in 1987 by 0.9 degrees.

"We saw it coming from mid-January on that we were seeing something quite remarkable," Whitewood said.

The experience has been similar south of the border, where the U.S. National Climatic Data Center said the winter has been the fifth warmest on record. December through February are considered meteorological winter.

It was especially balmy in Alberta, Saskatchewan and the Northwest Territories, where temperatures were 6 to 8 degrees above normal.

Whitewood said the last 10 winters have been warmer than normal and, along with this winter, reflect a trend that could be explained as global warming.

He said Environment Canada would spend the next year examining the data to see if it's an aberration or evidence of a trend.

While some Canadians have been delighted by the milder winter, many are disappointed about thinner ice for ice skating and hockey and less snow in the ski resorts.

Several islands off Nova Scota were inundated by thousands of pregnant seals forced to give birth on shore by unusually mild weather that has prevented the Gulf of St. Lawrence from freezing.