About what to wear in Nepal while travelling it depends on the climate. Nepal experience wide range of climates. However medium-weight and easy-to-wash cottons can be a good choice year-round if you are doing tour in Kathmandu valley, Pokhara, Chitwan and Lumbini. For tour in those destinations from October to February woolen sweaters, jackets or similar other warm outfits are necessary.  Short or long-sleeved shirts are good for March through May.  From June to September, light and looses garments are advisable.

If you are doing trekking you should have adequate clothing to keep warm. All most trekking routes are close to high Himalayas. So there normally weather is always low. In winter time (Dec, Jan, Feb) it is colder at night and can be foggy in the early morning. Wool jumper, sweater / fleece, loose trousers, gloves, thick socks, wind and waterproof jackets, track pants, good walking boots with ankle support, sleeping bag, sun hat and sun glasses are advisable. Down jackets and extra warm clothing (thermals) are suggested in winter season. For trekking if you do not have warm clothes and gears, you can always buy or rent them from one of Nepal’s many trekking shops in Kathmandu. Much of the clothing available is of adequate quality and rental charges are generally not excessive.