Himalayan weather depends mostly on altitude and season. Temperature drops about 6 C for every 1,000 m you climb, the monsoon brings rain from June to September, and the clearest, most settled weather is in October and November and again from March to May.
The four trekking seasons
- Spring (March to May): warming days, rhododendron in bloom, some afternoon cloud and haze lower down. A main trekking season.
- Monsoon (June to September): warm and wet on the south side, with cloud, leeches and landslides. Rain-shadow areas such as Upper Mustang and Dolpo stay much drier.
- Autumn (late September to November): the clearest skies of the year after the rain has washed the air. The most popular season.
- Winter (December to February): cold, dry and usually clear, with snow closing some high passes.
Temperature and altitude
The simplest rule is that air cools by about 6 to 6.5 C for each 1,000 m of height. If it is 20 C in Kathmandu at 1,400 m, expect about 8 C at Namche Bazaar (3,440 m) and around minus 4 C at Everest Base Camp (5,364 m) at the same moment, before wind is counted.
Nights are much colder than days, because thin, dry air loses heat fast once the sun goes. A sunny afternoon at 4,000 m can feel warm in a T-shirt, and the same spot can be minus 10 C before dawn.
Typical temperatures by height in Nepal
These are rough ranges for the main trekking months of October, November, March and April.
- 1,000 to 2,000 m (Kathmandu, Pokhara, the lower trail): days 18 to 26 C, nights 5 to 12 C.
- 2,500 to 3,500 m (Namche, Ghorepani, Lukla): days 8 to 16 C, nights minus 3 to 5 C.
- 3,500 to 4,500 m (Dingboche, Manang, Annapurna Base Camp): days 3 to 12 C, nights minus 10 to minus 2 C.
- 4,500 to 5,500 m (Gorak Shep, Thorong La, Kala Patthar): days minus 5 to 5 C, nights minus 18 to minus 8 C.
In January and February take about 5 to 8 C off each figure.
Himalaya temperature in winter
From December to February the high country is properly cold. Night temperatures at 5,000 m often fall to minus 20 C or lower, water pipes freeze in lodges and some high lodges close. Days are short but often brilliantly clear. Lower routes such as Poon Hill, Ghandruk and the Everest View trek to Namche work well in winter with warm clothing, and passes above 5,000 m such as Thorong La and Cho La can be blocked by snow.
For the summit of Everest itself the figures are in a different league: see Mount Everest temperature.
The monsoon and the rain shadow
From June moist air from the Bay of Bengal meets the range and is forced upward, and it drops most of its rain on the southern slopes. Pokhara, at the foot of the Annapurna range, is among the wettest places in Nepal. Behind the main peaks the air is dry: Jomsom, Upper Mustang and Dolpo get only a small fraction of that rain.
The eastern Himalaya gets the monsoon earlier and heavier than the west, which is why Sikkim and eastern Nepal are greener than Ladakh.
Snow, wind and the jet stream
The snow line in Nepal sits at about 5,000 to 5,500 m in the main seasons. Fresh snow can fall at 3,000 m in winter and after storms at any time of year. Above 7,000 m the main hazard is wind: for most of the year the jet stream blows across the highest summits, and climbers wait for the short calm spells in May when it shifts north.
Trekkers feel a milder version on high passes, where the wind usually rises late in the morning. That is the reason for early starts on pass days.
Is the climate changing?
Measurements across the range show that the Himalaya is warming faster than the world average, and most glaciers are shrinking. For visitors the practical effects are less predictable seasons, more late-monsoon rain in some years, and glacial lakes that are watched closely. It is one more reason to keep a spare day in any itinerary.
What this means for planning
Pick October to November for the clearest views, March to May for warmer days and flowers, and winter for quiet trails at lower altitude. Pack by height, not by month: a warm down jacket and a sleeping bag rated to about minus 10 C or lower are needed above 4,000 m in every season. See the Nepal packing list by season and Everest Base Camp temperatures by season.
Common questions
What is the temperature in the Himalayas?
It depends on height and month. In the trekking seasons expect 18 to 26 C by day in the foothills, about 5 to 12 C at 3,500 m and around or below freezing at 5,000 m, with nights 10 to 15 C colder.
How cold are the Himalayas in winter?
At 5,000 m night temperatures commonly reach minus 20 C in January, and on the highest summits the average is far lower, with severe wind chill.
Which month is best to visit the Himalayas?
October and November have the clearest skies. March, April and May are the second season. In India's dry trans-Himalayan areas such as Ladakh, June to September is the season.
Does it snow in the Himalayas all year?
Above about 5,500 m snow can fall in any month and the highest peaks stay white all year. In the valleys where trekkers sleep, snow falls mainly from December to March.
Heights, dates, fees and rules are approximate and can change, so confirm the current details with us before you book.
