The ideal times to visit are October to December, when the post monsoon mountain air is clear and fresh, or February to April when the climate remains dry and pleasant and the famous rhododendrons grow and bloom.
Visitors in January and February should be prepared for cool nights, but the Kathmandu hotels and luxury lodges are heated and the lower visitor numbers mean the trekking trails are generally free of large groups.
From May, heat and humidity build until June when the monsoon rains arrive.