Nepal has five seasons (winter, spring, summer/monsoon, and autumn), and weather and climate vary from one region to another as per the season. There are climatic variations in Nepal according to the geographical structures of the country as the Himalayan, Hilly, and Terai (plain lands) regions. It is pretty hot and humid in the lower region, moderate in the hilly region, and cold in the alpine region. Nepal has four climatic seasons.
Autumn (September to November)
From mid-September to the end of November, welcome to the autumn season. The weather usually is a little humid, with warm and sunny days. It is the best time of the year to trek in the Himalayas. With stable weather and a moderate climate, the trek becomes fantastic. The views are clear, and the trails get decorated with a range of colorful flowers. Sometimes the temperature falls to 0 °C.
It is the most popular trekking season in mountainous, high-altitude areas. The autumn days are warm with clear skies, but the nights are cold. In high elevations, the nighttime temperatures may even drop below zero degrees. The mountain views are surprisingly clear. So you can enjoy the amazing views of the mountains, landscapes, and more.
Winter (December to February)
(End of November to end of February) Winter is, of course, the coldest time of the year. The heavy snowfall and snowstorms in the mountains and unclear visibility make trekking unpleasant. Kathmandu and the Terai region do not receive snowfall. However, morning and nights get quite cold. The temperature falls below 0 °C in the mountains.
The winter season brings in stable weather and mostly clear skies, making it conducive for trekking in lower trek regions. The higher trek regions experience heavy snow and low temperatures. Daytime temperatures are cool, while nights are often freezing. Though the days are generally clear, snowstorms can occur, especially in the high Himalayas. Hence, we advise you to trek only in lower altitudes. This season is ideal for travel to Terai, Kathmandu Valley, and nearby areas, which do not experience snowfall.
Spring (March to May)
Spring, from March to May, is the second-best time of the year to trek in Nepal. Moreover, most of the 8,000 expeditions occur in this season and extend up to May. The trail blooms with beautiful flora, and the climate begins to warm up after an extreme cold.
During the spring, the skies are clear, the temperatures are just right, and the fresh snow on the mountain peaks looks inviting. Hence, thousands of people come to enjoy the trek. If you trek during this season, you can enjoy the greenery along with rhododendron, jasmine, and pine blooms.
Summer (June to August)
Summer/monsoon (June to September) is not a good time to travel in most parts of Nepal, especially in the mountains. The heavy rainfall not only ruins the views but also makes the trail slippery and prone to landslides. There are two regions where you can trek in the monsoon: Upper Mustang and Dolpo. These two regions fall under the rain shadow area, and because of that, both regions do not receive any rainfall in the monsoon.
The monsoon coincides with summer. The monsoon clouds block the views. Summer days are hot, and it rains almost every day. The trekking trails usually are muddy, and the leeches are active. This season is suitable for trans-Himalayan region hikes in Mustang, Dolpo, and so forth, as these areas lie in a rain shadow