All though not as popular as the winter venues in Northern Snowdonia Cadair Idris holds some fine winter climbing. The only real downside is that it does not come into condition as regularly. To grab a route down here you need to wait for a period of really sustained cold weather – once that happens though there are some real gems to be had.
Cyfrwy is famous for the much discussed (but rarely climbed) Trojan – a splendid but fickle grade V ice route. Cyfrwy Arete II also gives a good buttress style route if well snowed up.
Elsewhere on the mountain there are several good gully lines, such as East Gully IV and West Gully IV on Twr Du. The Great Gully IV in Cwm Cau is another classic of the area, but again it needs really good conditions to be worthwhile.
A few modern mixed routes have been added in recent years – these can be a good option in leaner conditions.
In a colder climate Cadair Idris would be a premier winter climbing venue. As it is the isolated position and closeness to the sea limit the occurrence of reliable snow and ice conditions – both of which are essential for the classic routes.
The main Cadair Idris crags can be reached from the road in an hour or two (depending on the amount of snow. For Cyfrwy approach from the Gwernan Lake Hotel side of the mountain, and for Cwm Cau approach from the A487 at the Idris Gates car park.