The weather in Nepal can be divided into four main seasons, which are autumn, winter, spring and summer – otherwise known as the monsoon season.
June to September is considered the summertime, or monsoon season, and the daily forecast typically consists of extremely high temperatures and intermittent rainfall. Summer is a good time to explore the cities, but trekking conditions are not ideal as the rain can lead to flood trails and mud slides. By the end of the monsoon season however, the countryside can be seen lush and green, offering the perfect lead-in to trekking season.
From September the climate begins to change as the country welcomes autumn, which lasts from October to November. These couple months are much drier with pleasant temperatures in the day time and good visibility. This time of the year is considered the best to go trekking in the Himalayas thanks to the fresh air and clear skies.
The winter months from December to February tend to be mild in the daytime but can become very cold at night, especially in the mountains. While winter is still okay for trekking with clear visibility, January is the coldest month of the year and sees many mountain lodges shut down due to the extremely low temperatures. The cities remain clear and chilly, though without snow it is easy to explore the city sights.
Spring appears from March to May with pleasantly warm temperatures and occasional showers – this is also considered a good time to go trekking with longer days. Flowers begin to bloom during this time and it is also a wonderful time of year to spot wildlife. The annual temperatures peak in May just before the monsoon season begins.