Travel time: Year-round
Nepal’s climate is defined by some of the most dramatic vertical geography on Earth. In a span of less than 200 kilometers, the landscape ascends from near sea level to the roof of the world, compressing every major climate zone—from tropical to arctic—into a single nation.
Altitude is the primary architect of Nepal's weather. Travelers essentially move through different worlds based on their elevation:
While many countries follow a four-season model, Nepal operates on a traditional five-season cycle influenced by the South Asian monsoon.
This is a period of transition and awakening. For every 1,000 meters of ascent, temperatures typically drop by about 6°C. In the lower hills, the famous rhododendrons begin to bloom. High-altitude trekking becomes viable as snow melts, though cloud cover often increases in late afternoon, sometimes obscuring the views.
In the lead-up to the rains, the Terai and central valleys experience intense heat. Dust levels rise, and the air can feel heavy and hazy. This period often sees "heat lows" that trigger sudden, violent afternoon thunderstorms and hailstorms, particularly in the foothills.
The monsoon brings 80% of Nepal's annual rainfall. It is not a continuous downpour but rather a series of heavy afternoon and evening rains separated by humid, sunny intervals. The landscape turns a brilliant, deep green, but the humidity is high, and visibility of the mountain peaks is rare. Cloud-bursting rain is common, which locals rely on for the survival of their staple rice crops.
Widely considered the most stable period, the post-monsoon air is washed clean of dust and moisture, resulting in exceptionally blue skies and the sharpest mountain views of the year. The weather is crisp, with cool mornings and warm, sunny afternoons.
Winter is characterized by clear, dry weather. While the mountains are buried in snow and endure sub-zero temperatures, the valleys like Kathmandu experience sunny days but very chilly nights. A specific phenomenon called the "Winter Fog" often settles over the Terai and Kathmandu Valley, sometimes lingering until mid-day and making the air feel much colder than the thermometer suggests.
Life in Nepal is a constant negotiation with the environment. In the mountains, stone houses are built with thick walls to trap the afternoon sun for warmth at night. In the Terai, traditional architecture features high ceilings and shaded porches to combat the tropical heat.
Locals have observed shifting patterns in recent decades, noting that the monsoon now often arrives later and stays longer than its traditional mid-June to September window. This "shifting monsoon" affects everything from agricultural cycles to the timing of major festivals like Dashain.
In Nepal, the sun is your heater. In the thin air of the mountains, the "feel-like" temperature can fluctuate by 20 degrees based on whether you are standing in direct sunlight or the shade. Even in the dead of winter, a sunny day at 3,000 meters can feel energetic and warm, but the moment the sun dips behind a ridge, the chill is immediate and biting.