Nepal has four distinct seasons. Spring from March to May, is warm with rain showers. Summer, from June to August, is the monsoon season when the hills turn lush and green. Autumn, from September to November, is cool with clear skies and is the most popular season for trekking. In winter, from December to February, it is cold at night, with fog in the early morning.

Because Nepal is quite far south in Latitude (same as Miami), the weather is warmer and winter is much milder at lower elevations. The monsoon is determined by the Bay of Bengal. It is hot during the monsoon with rain almost everyday. During this season, trekking in most of Nepal is difficult and uncomfortable, the trails being muddy and infested with leeches. It usually does not rain for more that one or two days during the entire autumn and the winter season. In the winter, the mountains are covered with snow including some high hills. Mt. Everest itself is a huge black rock during the trekking season, which becomes snow-covered only during the winter.