The Soča valley is at its most dramatic in late spring and early summer (May to July), when the river runs full from snowmelt and the surrounding mountains are still snow-capped. White-water conditions are best in May and June. The water temperature rises enough for comfortable swimming by July and August, which are the peak months — the valley fills with visitors and accommodation should be booked well ahead.
September and early October are excellent: the crowds thin, the light softens, and the beech forests on the valley sides turn gold. White-water rafting continues until late October. Winter brings skiing on Kanin from December; the valley floor is often clear of snow even when the resort is fully operational.