Wusong Island Rime Ice

Water released from the Fengman dam keeps the Songhua river above freezing through the Jilin winter, so mist rises from it into air that can be minus twenty or colder, and the vapour deposits directly onto the willows and pines along the bank as rime, building feathered white crystals several centimetres thick overnight. The effect appears on perhaps forty to sixty mornings a winter, forms before dawn and can drop off within hours of sunrise, so viewing means arriving in the dark and waiting in extreme cold. Wusong Island, an hour from Jilin City, is the favoured spot, with photographers lining the bank. Local practice holds that a still, humid, very cold night predicts a good morning.

What you actually see

• The rime-coated trees - willows and pines feathered in thick white crystals.
• The river mist - vapour rising from water kept liquid by the dam.
• The dawn light - the short window before the rime falls away.
• The photographers' bank - the crowded riverside at first light.

When to go

December to February, arriving before dawn; the phenomenon is unpredictable and appears on only a portion of winter mornings. Local forecasts and hotel staff give the best indication the night before. Temperatures of minus twenty are normal.

Honest expectations

The rime does not form every night and many visitors see bare trees. Viewing requires being outside in extreme cold before sunrise. The site is crowded with photographers on good mornings, and tour buses arrive together.

Nearby

Jilin City lies southwest; Changbaishan is far southeast.