Rivers are graded for difficulty on an interaction scale from 1 to 6, class 1 denotes easy-moving where as class 6 denotes nearly impossible. All graded rafting and kayaking is performed in Nepal. The most popular river by far is the Trishuli in central Nepal which draws 90% of rafters.

          July to August is monsoon season in Nepal. During this season the Rivers are at greatest size, more than 10 times greater than in February and March. So to attempt any rafting and Kayaking during this time require high courage and real experience. After the monsoon season the exciting and adventurous rafting begins till November. At that time the weather is settled and the water current is rapid and powerful. In winter the water is very cold and also rafting is very short due to short days. The best months for rafting are March and April with long & warm days in excellent spring season with splendid views of the icy mountains, diversity of landscape, peoples, customs, culture and language

Among these rivers, Sunkoshi, Bhote Koshi , Karnali and Tamur are highly recommended by Rafters while Trisuli, Kali Gandaki, Marsyangdi, seti and Bheri are recommend by many Rafters and in Arun river you need the specialist interest