Nepal’s climate varies with its topography and altitude. It ranges from the tropical to the arctic. 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 mid-land regions are pleasant almost all the year round, although winter nights are cool. The northern mountain region, around an altitude above 3,300m has an alpine climate with considerably lower temperature in winter as can be expected.seasons
Nepal has four climatic seasons.

Spring (between March – May): The temperature is mildly warm in low lands while moderate in higher altitudes with plenty of opportunities to have tryst with the mountain views. It is also the time for flowers to blossom and the national flower of Nepal – rhododendron sweeps the ascending altitudes with its magnanimous color and beauty.

Summer (between June – August): This is also the monsoon season in Nepal. The weather is hot and wet at times. It rains almost everyday with occasional thunderstorms in the evening. The rain spreads the pleasantness around with lush green vegetation.

Autumn (between September – November): This is the best tourist season in Nepal with the summer gone by and the winter to set in. The weather is highly pleasant so are the mountain views. This is the peak season for trekking as mountain views are guaranteed so better book your flight in advance. This is also the season of festivities as Nepal celebrates the biggest Hindu festivals Dashain followed by Tihar.

Winter (between December – February): The weather is cool and the sky is clear with occasional snowfalls at higher elevations. This season is good for trekking in lower elevations. The morning and night is cold and the days are warm when sunny.

temperature & 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.