Reuters reported that the harshest winter on the mainland China in nearly three decades has hit iron ore output and driven up prices just as demand from steel mills revives in a resurgent economy. Imports are at record levels.

According to a survey by consultancy Mysteel published on December 28th “The harsh weather conditions have halved utilization rates at private mines and processing plants in some areas.”

Mr Henry Liu head of commodity research at Mirae Asset Securities in Hong Kong said that “Up to 15% of iron ore mines, especially those in the north, where it has been coldest, remained shut. Many small mines and processing plants closed last year after iron ore prices slid to three year lows and made more costly producers unprofitable. When prices rallied last month, it was already too cold for them to resume production.”

Mr Liu said that "They would want to return to production, but they can't because of the weather. We estimate 10% to 15% of these local mines are still closed because of the cold weather."

Temperatures on the mainland have plunged to their lowest in 28 years, icing coastal waters, canceling flights and closing highways. Once a thaw arrives, however, prices will likely come under pressure as mainland miner’s return to full production.