The warmest months are June to September. May and October can be several degrees colder than the figures above.
Wind chill rating: Medium
If you are on a supported trip, weight will not be quite so crucial. If you are transporting your own gear on foot, then weight and bulk will be important.
Fleece is usually recommended as the insulating layer for this humid climate. We have included the Sigma Pullover and Vest as warm options for cool camps, as the Thinsulate insulation is well suited to damp conditions and the shell is much more windproof than fleece. Either garment will pay its way, warmth for weight.
Looking for a guided trip with an experienced company? We recommend KE Adventure Travel's Three Peaks Challenge.