Nowhere in the world is the climate so distinct and poles apart. The long stretch of the northern frontier, which is mostly rugged terrain, towered by the mighty Himalayas experiences arctic type of climate and a few hours down south at the fringes of the Indian borderlands the landscape and climate changes dramatically as the elevation decreases. With lush green tropical forests and vast stretches of plains one can encounter hot humid climate.

The year is divided into 4 different seasons in Nepal - winter, spring, monsoon and autumn. The best period to visit the country for plant lovers is during spring when the flowers are in full bloom. The mountain slopes are covered with beautiful and colorful flowers. Spring season commences from early March and continues until late May. Even though the days are clear haze disturbs the mountain views. Late May, and the downpour begins. It continues till late August. Come September and the autumn season begins. It continues till late November. With temperate climate, clear blue skies and extraordinary mountain views it is the best season to visit the country. Winter begins in late November and continues till late February.

Temperature and rainfall 

Nepal is the country of extremes. The low-land plains of the Terai can have tropical temperatures and also the mosquitoes. The Himalayas can get to sub-zero temperatures, but the sun blaze can bring some warmth during the day, even in the mountains. The temperature of Kathmandu goes below 1 Degree Celsius (34 Degree Fahrenheit) in winter and rises to an average of 25 Degree Celsius (77 Degree Fahrenheit) in summer.

The average temperature in Kathmandu during the four seasons:
Spring season ranges between 16-23 Degree Celsius (61-73 Degree Fahrenheit)
Summer season ranges between 23-25 Degree Celsius (73-77 Degree Fahrenheit)
Autumn season ranges between 15-24 Degree Celsius (59-75 Degree Fahrenheit)
Winter season ranges between 9-12 Degree Celsius (48-54 Degree Fahrenheit)

During the rainy monsoon season between June to August, it rains to an average between 200-375 millimeters in Kathmandu. There is occasional rainfall during the other seasons too. In an average, 1300 millimeters of rain falls in Kathmandu every year.
Travel Tips: Monsoon in Nepal is not the typical monsoon of Asia.