The Meteorological Agency revised its prediction Thursday and said this winter would be the coldest one seen in the past two decades.

The agency had said earlier this winter would be warm, but changed its tune after record-low temperatures were posted across the country this month.

It also said snowfall will be heavier than usual from December to February on the Sea of Japan coast.

In the 1985-86 winter, temperatures were lower than normal and snowfall was heavier.

The national average temperatures measured from Dec. 1 to Dec. 20 came to 2.6 in eastern Japan -- matching the record low recorded in 1946 -- and 3.0 in western Japan, matching a 60-year low. The average temperature in northern Japan came to 1.9.

Weather forecasters said the new projections stemmed from the extreme difficulty they had in predicting the movement of the polar cold air system and it could not be expected to stay over Japan much longer this month.

The Meteorological Agency also issued a three-month weather forecast that said temperatures would be low or average for the entire country in January and average or high in February.

In late November, the agency predicted a warm winter, with temperatures within normal range or higher in eastern and western Japan.