Trekking seasons are as used Nepal for all seasons. There are four seasons in Nepal, each season having different attractions for hiking and trekking. But the most pleasant and favorable season to visit Nepal is Autumn and Spring among other seasons. The four distinct seasons of Nepal are as follows:
Autumn (September to November)
Trekking seasons in Autumn is considered to be the best season for trekking as during this period the weather is excellent and the mountain views are clearer. Trekking seasons of this time is the highest and crowded so far.
Winter (December to February)
As it snows in winter, it is difficult to trek at higher elevations. So, trekking at lower altitudes especially below 3000 meters is recommended during this trekking seasons. This time trekkers can trek around Pokhara like Ghorepani poon hill, Royal trek, around Kathmandu such a chisopani Nagarkot trek as well as Chandragiri hiking and tour around Kathmandu valley, Chitwan jungle safari, Lumbini pilgrims tour, Tansen palpa and Pokhara tour.
Spring (March to May)
Spring is another great season to trek because of the excellent weather and clear mountain views. This season is also high season for expedition, thousands of mountaineers summit Everest and other similar peak during this season. Wildflowers like Rhododendron are in full bloom in spring season, and they can be seen in most of the trekking trails across Nepal.
Summer (June to August)
Due to the monsoons in summer trekking is generally not recommended during this season. However, keen botanists may find it worthwhile to trek at lower altitudes during this season because of the blossoming wild flowers and lush vegetation. Nepal and Tibet has some of the rain shadow region such as Upper Mustang, Upper Dolpo, Humla and Mount Kailash in Tibet. So, you will not face any kind of problems to visit these region even in monsoon season.