Climate and weather vary according to  the season in Nepal. The winter season which falls from the end of November to March, when the weather is stable and the sky is generally clear. It is the coldest weather. During this season the mist is often found in the valleys and reaches the Himalayas, which makes the sky not very clear, but  possible to do trekking in the low altitude areas, because  of snow falls abundantly in the high altitude areas, which makes it difficult for travelers to walk, and  unobstructed views of the mountains etc. But it does not snow in Kathmandu and Pokhara valley,  you can travel to the Terai plain.  Notice that in morning and in evening it is really cold, you have to be prepared for a bad weather.

Autumn begins from mid-September to late November, during this season weather is a bit humid with sunny days and warm nights. This is the most popular season for trekking or tours. During this season, the hills seem too colorful and the sky is clear with amazing views including the mountains, landscapes etc. Due to amazing weather, major trekking trails in Nepal are Everest, Annapurna, Langtang region etc.

Spring is another most popular season for trekking, which falls from March to May. The weather is warmer and the day is long. The rhododendron flowers are blooming which makes the trail beautiful and amazing. This season is particularly suitable for trekking in high altitude areas, including climbing and expeditions.

The summer season, which falls from June to September, is a bit difficult to navigate in Nepal. During this season it rains heavily and people avoid trekking, but in Nepal there are many rain shadow areas like Mustang, Dolpo regions where it rains little. But the mountain areas are covered with fog and rain almost every day, the trails are slippery, also the leeches are active, and therefore create difficulties to have a better sky and landscape. However, this season is a really an amazing season because there is greenery everywhere, the valleys are filled with flowers and butterflies.

Autumn (mid-September to end November)
This is the most popular season for trekking in mountains or at high altitudes. Usually in autumn the weather is a little warm with clear skies or the days and nights are a little cold. At altitude the nights sometimes even go down to zero temperature. In this season, the views of the mountains are amazingly clear, so you can get some amazing views, including mountains, landscapes, and more.

Winter (late November to March)
During this season, the weather is stable and the sky usually clear, it is suitable  and possible to go hiking. During the day the temperatures are cool, but at night often very cold and freezing. The days are generally clear but often there are thunderstorms and freezing snow. As it snows heavily in the high Himalayas, it is possible to hike in the lower elevation areas. Since it does not snow in Kathmandu and the Terai plain, this is the best seasons to travel there.

Spring (mid-March to May)

Usually clear in morning but the clouds cover the sky in the afternoon and sometimes it rains too. During this season, you can have amazing greenery when flowers such as rhododendron,  Jasmine, Pine etc. are blooming. It is the second most popular season for trekking because the weather and climate are so wonderful and pleasant.

Summer (June to mid-September)
This is a monsoon  Season, in the morning usually cloudy, and in the day all the ridges and Himalayas are covered by clouds, which makes the views difficult and uncomfortable. The weather is warm and it rains almost every day. The hiking trails are generally muddy, landslide and leeches in long herbs are often active. During this season, it is only possible to travel to the Trans-Himalayan regions of Mustang, Dolpo etc. These regions are in the rain shadow, and therefore receive significantly less rainfall  like Tibet, more desertic than other parts of the country.