There are different array of climate in Nepal and make sure to look at the weather update before packing your bags. There are no such things as “not wearable clothes”, be sure you are culturally sensitive when you are in the rurals. You can wear the clothes of your choice in Kathmandu and other major cities where as you have to be culturally sensitive when you are in remote. If you forget to pack some essential stuff there is no need to panic you can buy almost everything you require in Nepal.