The weather on Mount Everest follows four seasons. Spring (April and May) and autumn (October and November) are the best for trekking. The summer monsoon brings cloud and snow on the mountain, and winter brings extreme cold and wind. Climbers use a short window in May.
January and February
These are the coldest months. Summit temperatures are far below minus 30 C, and the jet stream passes over the peak. Trekking is possible but cold, with some lodges closed above Namche.
March
Temperatures start to rise and the skies are often clear in the mornings. Cold nights remain. It is the start of the spring season, and trails are quiet in early March.
April
This is a popular month for treks. Days are mild in the lower valleys, and rhododendrons flower. Afternoon cloud builds on some days.
May
The weather window for climbers falls in May, when winds on the summit can fall for a few days. Trekkers see warmer days, but haze and afternoon cloud are common, and the monsoon nears by the end of the month.
June to September
The monsoon brings heavy cloud and rain, and snow high on the mountain. Views are rare and flights to Lukla are often delayed. Few trekkers go.
October and November
These are the best months for clear views. The air is dry, the sky is blue and the temperature is stable. Nights are cold at altitude. Autumn is the busiest season, so book early.
December
Days are usually clear and sunny, but nights are very cold. It suits experienced trekkers with proper kit.
The jet stream
In winter, the subtropical jet stream sits right over Everest and blows at very high speed. In late spring it shifts north, and the mountain has a short period of calmer wind. This is the main reason expeditions are timed for May.
The monsoon
Moist air from the Bay of Bengal reaches the Himalaya in June and lasts until September. The rain falls mostly below 4,000 m, and snow falls higher up. Clouds make mountain views rare, but the valleys are green and the flowers bloom.
Choosing a month
If you want the clearest views and steady weather, choose October or November. If you want warmer days and flowers, choose April. If you want fewer people, consider early March or early December, and accept the cold.
A note on climate change
Glaciers in the region are retreating and weather patterns are changing, so past patterns are a guide, not a promise. Check forecasts a few days before you fly, and keep a spare day in your plan.
Plan it
See the best time to trek to Everest Base Camp and temperatures by season.
