Altitudes affect Nepal’s regional climate, which is temperate alpine on the lower mountain ranges and subtropical in the Terai, south towards India.
The peak tourist season is autumn (late Sept to late Nov). The weather remains clear and dry, and temperatures are comfortable, neither too cold in the mountains nor too hot in the Terai.
The monsoons leave behind clean air, making for great mountain views. It is an excellent time for trekking. For the culturally minded visitor, Dasain and Tihaar are the two major festivals during this period. Being peak season, early bookings are advisable due to high demand.
December, January and February are usually very cold, but will reward visitors with clear skies, incredible views and quieter trails.
March and April are also very popular months for travel as spectacular rhododendrons bloom in spring.
The weather is mostly clear and stable. Day temperatures are pleasant but plunge significantly at night-time, especially in the mountains.
January is the coldest month with average temperatures of 6°C in Namche Bazaar, but fewer visitors result in quieter trekking trails and sightseeing opportunities.
For those who can withstand the winter cold, it is a good time to be in the mountains but some lodges shut down as owners escape the fierce cold. You’ll also be rewarded with clear skies and incredible panoramas. High altitude trekking is not recommended at this time.
Kathmandu doesn’t see any snow during winter but are dank and chilly. fierce cold can make lodge owners shut up shop altogether.
October-April is an excellent time to explore Nepal’s wildlife in the Terai reserves of Chitwan and Bardia, offering excellent chances to see Rhinos, Tigers and Elephants.
Temperatures increase and several varieties of rhododendrons bloom in Spring, their colours differing according to altitude from reds to pinks and whites.
The longer days are perfect for trekking, although night time temperatures are still cool.
As temperatures and humidity rise, haze can affect the mountain views from lower altitudes. May is one of the warmest months (up to to 35°C in Chitwan National Park) but can bring pre-monsoon cloud and showers.
Spring is the best time for viewing wildlife despite the increasing heat as the Terai’s long grasses are cut down.
The Hindu festival of colour, Holi is celebrated across Nepal every March.
Monsoon rains usually arrive by mid-June and last till mid-September, bringing warm and humid days.
The rains create an extraordinarily pretty scene, lush green landscapes with flowers blooming, fresh air, butterflies everywhere, and the markets heaving with fresh fruit and vegetables.
Trekking is not advisable during the monsoons. The clouds obscure mountain views, leeches abound on the mid-elevation trekking routes, and travel is often disrupted.
As in neighbouring Bhutan, the mountainous topology results in monsoonal rain often falling during the night, resulting in beautiful mornings and good conditions for cultural holidays, as long as you don’t stick to the main routes and insure against travel disruptions by having some slack in your itinerary.
October and November are two of the best months to visit Nepal, with the monsoon leaving behind beautiful clear skies, fresh air and incredible views. The dry days are made for trekking. The weather remains dry all the way to April with some temperature variations across the regions.