Climate

The trekking season extends from late September until the end of May. During the monsoon (June to September), trails are very wet and the clouds obscure views, making trekking unsuitable (unless you plan to trek in Upper Mustang, Upper Dolpo or Tibet).

The most popular time to trek or climb is in Autumn (October and November) after the monsoon. The air has been washed crystal clear by the rains, and the "weather is quite stable" and "expect warmer daytime temperatures" nights are cool, and skies clear. In these ideal conditions, Kathmandu and the trekking trails can become quite crowded.

If you are going up to very high altitudes, you may not want to plan your trek for the heart of Winter (December to February). Night temperatures can be bitterly cold up high. But conditions are still pleasant on the lower trails, with crisp days and clear skies, and less trekkers about!

In the Spring (March to late May), expect warmer day temperatures, but hazy visibility and cloud cover are also more likely, especially in the afternoons. However, it is the season when the spectacular wildflowers blossom, including the wonderful rhododendrons.