The best seasons to trek in Nepal are Autumn, from early October until early December and Spring, from the beginning of March until the end of April. During Autumn, the weather is generally clear with mild to warm days and cold nights. In the Spring, the mornings are usually clear but afternoon cloud build-up brings occasional showers. The days are warm and the displays of wildflowers, such as rhododendrons, are spectacular at this time of year.
It is also possible to trek during Winter, from December until the end of February. Daytime temperatures will be cooler, however, and the nights will often be very cold. The days are generally clear but occasional winter storms can bring snow as low as 2500m.
Summer in Nepal , from June to September, is the monsoon season. Trekking at this time of year is generally difficult and uncomfortable as the weather is hot and it rains almost every day. The trails become muddy and are often leech-infested and the mountains are usually obscured by cloud.
There are, however, possibilities for summer trekking in the trans-Himalayan regions of Mustang, Dolpo and Tibet . These regions lie in a rain-shadow and therefore receive significantly less precipitation than the more southerly areas.
