The best and the most suitable time to visit for trekking, adventures, mountaineering, tours in Nepal are Autumns (September, October, November) and Spring (March, April, May). These are the most suitable time for anyone to visit Nepal. If someone visits Nepal in these seasons, then they will be awarded good weather, sunny and warm with clear blue sky and magnificent views. However, in the spring, it can get a little rainy. During monsoon, there can be a little rain which may leave muddy paths and leech-infested trails. The mountains will also be hidden by clouds. Despite this, the hills in monsoon turn lush and green and the mountains and meadows blossom with flowers and abundant vegetation. You can also trek in winter, but the problem in winter is the cold weather and the snowfall at the higher altitude. Over the past few years, trekkers and travelers have found the early winter the most suitable season to visit.
Rain Shadow Area Trekking
There are trans-Himalayan regions such as Mustang and Dolpo towards the north-west of the Dhaulagiri Mountain range in Nepal. These regions get less precipitation as the cloud flowing from the south is blocked by the Himalayan range. So these regions lie in the rain shadow. Trekking can be organized in this area even in the summer/monsoon season.
This area gets crowded during mean seasons i.e. spring and autumn but in the monsoon or winter season, it is less likely to have a crowd, so one can enjoy nature to its full potential. If someone wants to avoid crowds in the best season, then they have to start the trekking at the beginning of the end of each season.
More on climate in Nepal
Nepal has different climates and topography. The altitude ranges from 80 m to 8848 m concerning the sea level. The southern plains are hot most of the year; the temperature gradually decreases towards the North as the altitude increases.
This is a great season to visit Nepal. This season starts from mid-September to end-November. It is a suitable time to trek since the weather is clear with mild to warm days and cold nights. However, it can get a bit chilly during nights and can drop into freezing temperatures. The view of mountains is clear in this season. This is also the time of the year where Hindus celebrate their festival Dashain followed by Tihar.
The weather is usually cold during winter but the sky is usually clear. The snowfalls at a higher elevation. Trekking is possible during winter, from December until the end of February. This season can be really good for trekking in lower elevations but trekking can be challenging due to weather during this time as it gets too cold and irregular snowfalls followed by winter storms.
Spring and early Summer
The mornings in spring as usually good with a clear sky but in the daytime, clouds can bring occasional showers. This period is also considered as a suitable time for trekking as the hills are snow-free and the climates are good and warm.
The monsoon starts in June and ends in September. This is the time of the year where you do not see people around for trekking. This is because the sky is usually cloudy and the weather is rainy. It can be hard to trek since it is always raining and the climate is hot. The trails become muddy and infested with pesky leeches. The mountains are usually covered with clouds and there are chances of thunderstorms, hail shower throughout this season. Despite this, there are trans-Himalayan regions like Mustang, Dolpo, and Tibet since these areas lie in a rain-shadow and therefore receive less precipitation than the more southerly areas.