Nepal is a paradise for all adventure and nature lovers. You can visit Nepal all throughout the year as the beauty of Nepal can be enjoyed throughout the year. Spring (March, April, May) and autumn (Sept, Oct, and Nov) are the best time to visit Nepal. During these months the weather pleasant with efficient sunlight and warmth. The sky is clear which means you can enjoy the remarkable Nepalese landscape complete with Himalayan Vista.
During monsoon (June, July, Aug) there is no problem trekking, however, the visibility could be less because of the rain. If you are a keen botanist, monsoon could be the ideal time for you to trek as it is during these time when the mountains and meadows blossom with flowers and thick vegetation. Another good reason to trek during the monsoon is that you will have the trail all to yourself. Their trails will not be overcrowded. Winter (Dec, Jan, Feb) is also good for trekking but as you go to higher altitude, it might get very cold. Global warming has changed the way nature behaves and Nepal is no exception to it. Be prepared for unpredictable mountain weather.
The best time to do Everest Base Camp trek
and Annapurna Base Camp trek
is either spring(March, April, May) or Autumn(Sept, Oct, and Nov). During the spring season, the trails will be covered with blooming flowers and the weather is excellent with clear blue skies. During Autumn, the monsoon clear away and the snow melts, leaving behind naked mountains with very less snow on them. Autumn is ideal for trekking and it is also one of the best seasons in Nepal for merrymaking and travel.