Weather is the first factor that determines your plan for any region of world. Nepal can be visited all year round. You can find good places for trekkings somewhere in the mountain region at any time of the year.
Although the average height of Pokhara is only about 200m, it represents a good topolographical diversity and the varied altitudes result in considerable climatic differences. As a result one can feel a diverse type of vegetation and climate even in a single day walk.
Nepal’s weather condition depends on the season and altitude of athe place. Weather is generally predictable and remains pleasant in Nepal.
Nepal experiences four seasons:
Spring : March-May
Spring season starts from March and ends in May. Days are warm with hazy mornings and temperature fluctuates between 20 *C - 30* C (68* F to 86* F). This is a good to trek in this season as the ascending altitudes gets colorful appearance by Rhododendron blooms and piled up snow starts to melt in the higher altitudes.
Summer : June-August
Summer starts from June and last for August. Nepal gets rain fall due to monsoon and summer is pre-monsoon and monsoon months with occasional evening-thunderstorms and hot temperature. During the monsoon it rains almost every day and visibility is poor. However, the beginning days of summer are warm and humid, you have better chance to visit Everest area but the late summer is rainy and best to trek the areas like Dolpo, Manang and Mustang as the areas lies in rain shadow.
Autumn : September-November
Autumn is busiest tourist season in Nepal. Many trekkers and climbers prefer autumn as best time to visiting Nepal. During the season, days are clear with fine weather, visibility is good, least rain, people in festive mood, mild temperature fluctuating between 20* C to 30* C (68* F to 86* F). This is the same season when the main festivals of Nepali, specially Hindu, Dashain, Tihar and Chhat are celebrated.
Winter : December-February.
Winter days are mostly clear, morning and evening are cold and afternoon is pretty sunny. The higher altitudes gets occassional snowfalls. The season is stilll suitable for trekkings in the lower regions. The temperature falls even lower than freezing point in mountain regions and fluctuates between 0* C to 20* C in valleys like Kathmandu.