The climate in Nepal varies with its topography and altitude; climate from the tropical to the arctic. Nepal has divided into three regions of Nepal (Tarai region, Hilly region and Himali region). The low-land Terai region with its maximum altitude to approximately 305m, which lies in the tropical southern part of the country, for instance, has a hot and humid climate that can rise above 45 Degree Celsius (113 Degree Fahrenheit) during summer. The hilly region regions are pleasant almost all the year-round, although winter nights are cool. The mountain region, around an altitude above 3,300m, has an alpine climate with considerably lower temperature in winter as can be expected.
This season is one of the best trekking seasons in Nepal which offers excellent weather and magnificent mountain views. All the trekking routes are will be very busy during this season.
This season is the second premium trekking season. At this time the temperature goes quite moderates, but this season is especially the rhododendrons (National flower of Nepal) are in complete blossom and the mountain views are excellent in the mountain region.
The summer season provides the preferable season to trek in the rain shadow areas like upper Mustang, around Annapurna, etc. these regions are out of reach of the rain clouds because of the huge mountains, and unaffected by the monsoon. This time is the best season for forest researchers and botanists, during this time for trek raincoat and insect repellents are strictly required.
The winter season is in Nepal will be cold in high mountain trekking routes but still suitable time for trekking and hiking at lower altitudes normally under 3000m high.