Generally speaking, there are two trekking seasons in Nepal. One right after fall with the other one right after winter.
Mid of September to mid of December are considered as the best trekking season in the Himalayas. During this time the climate is mild. Not too cold and not too hot with a crystal-clear view of the mountains.
The other great season is right after winter when the sun is getting warmer, and the spring condition makes trekking in the Himalayas bearable again. During the entire spring, many different flowers and trees start to bloom all over Nepal. No better time for climbing to the summits and explore spring’s bounty
1. Autumn (September-November)
This is considered to be the best trekking season in Nepal. September, October and November are the fall months. The weather conditions are excellent, and the mountains are tantalizing. The mild climate makes this time the number 1 season to explore the Himalayas. The sky is generally clear with breathtaking views. Occasionally there might be a short storm with considerable snowfall in high altitudes.
2. Winter (December-February)
Winter days in Nepal are usually clear days. The December, January and February months are extremely cold in the mountains. During the winter season, you might experience snowfall. Particularly in higher up regions. This makes those months ideal for exploring the Lower ranges. There is some stunning scenery to be explored.
3. Spring (March-May)
The spring season in Nepal is considered to be the best time ever for mountain climbing in Nepal. In this season, you can observe the different varieties of wild flora blossoming; you see the giant Rhododendrons above 3000m. Besides this, during this time Nepal is a hunting paradise. This makes the higher ranges a more interesting and comfortable trekking experience. It is mildly warm in the lower and moderately warm above 4000m. You will never forget the excellent view of the mountain and the magnificent photos you bring back home with you.
4. Summer (June-August)
June, July and August are the months of the monsoon in Nepal. The heavy rainfalls which come with it makes trekking dangerous and is therefore not recommended. However, this season is ideal to explore Nepal and its deserts where Nepal is adjoined to Tibet. This is the number 1 season to see the ,everest base camp. Gokyo trekking, Nar-Phu Valley and Dolpo regions. This time offers a great alternative, viewing the Himalayan behind the rain curtain.