You can go trekking in Nepal at any time of year; there are no restrictions. However, each season will give you a different experience.
You will need to prepare a bit differently, depending on which season you plan to trek (more below). There are two peak trekking seasons which provide you with the best views and weather, but also with more trekkers on the trails:
- Between late February-April (spring)
- Between late September-November (autumn)
You may also trek during:
- November-February (winter) which provides clear skies perfect for viewing the Himalayas, but much colder temperatures
- May-early September (monsoon) which provides amazing thunderstorms, but warm temperatures and more cloudy views