Nepal has two distinct seasons, a dry one, which lasts from October to May, and a wet monsoonal one from June to September. During summer, it can get very hot in May and June before the arrival of the rains. During winter, Kathmandu can encounter mild sunny days although the nights will generally be very cold; however it never snows in the Kathmandu Valley.

There are two main trekking seasons in Nepal, September to Early November, and February to late March/early May. In The first season promises clear days morning and afternoon, and a pretty good temperature in the foothills, with the downside being that this is the most popular time to go. The second season tends to be clear in the morning, and clouding over in the afternoon, but a similar temperature. The advantage being that less people are on the trail. From early November to February, the temperature can be very cold at higher altitudes, but there will be relatively few people on the trail.