Kathmandu, the capital of Nepal, sits in a bowl-shaped valley in the Himalayan foothills at around 1,400 metres above sea level, ringed by mountains, at approximately 27.72°N, 85.32°E. Its altitude tempers its subtropical latitude, giving it a mild subtropical highland climate (Köppen Cwb) — warm days and cool nights — with the year shaped above all by the summer monsoon that divides it into a wet and a dry season.

The warmest months come in late spring, around May and just before the monsoon, with highs in the high 20s°C and pre-monsoon thunderstorms building. The summer monsoon, from June to September, keeps daytime temperatures around 26–28°C but brings heavy, frequent rain, high humidity and thick cloud that often hides the surrounding mountains. Nights stay mild and the valley turns green under the rains.

Winter, from December to February, is dry, sunny and mild by day but cold at night, with January the coldest month — average highs around 18–19°C but lows near 2–3°C, occasionally dropping close to freezing, with frost possible on the coldest mornings. The large gap between warm, sunny days and cold nights is characteristic of the valley, and the clear, dry winter air offers the year's best views of the Himalayas.

Kathmandu receives around 1,400–1,500 mm of rain a year, roughly 80% of it delivered by the summer monsoon between June and September, when July is the wettest month; heavy monsoon rain regularly causes flooding and landslides in and around the valley. The winter and spring are largely dry and sunny. Live rainfall, humidity, and pressure readings for the city are shown in the panels above.

Kathmandu's weather is governed by its Himalayan-valley setting and the monsoon: the towering mountains to the north block cold Central Asian air in winter and wring heavy rain from the humid monsoon air in summer, while the enclosed valley traps both morning fog in the cold season and, increasingly, air pollution. Autumn, after the rains clear in October, brings the crisp, transparent air prized for mountain views and trekking.

To follow any single measurement in Kathmandu more closely, use our live instruments: the online barometer for atmospheric pressure, the thermometer for temperature, the hygrometer for humidity, the anemometer for wind speed, the wind vane for wind direction, and the rain gauge for rainfall.