Nepal is quite different places, the landscapes can vary from different places. Mostly when travelling to Himalayan region, it is the most prone to weather changes that takes place with out any notice.
With not proper GPS system in the airport, it is usually hard to travel by flight when there is heavy rain, thick fog, heavy storm etc, which always leads to delay or cancellation of flights.
As for good weather and less cancellation of flights, we recommend our guest to make their travel plan on Autumn season. In this season there is less frequent weather changes, by which it is easy to take off and land safely.
For other season is it hard to make sure the flight will be on time. So it be better to have some spare time in the plan of our trip so that it helps to make your flight the next day, when the flight is cancelled. Lukla is located in dramatic place so one should always be ready to face the unknown circumstances that arises during the trek.
And also on your return flight, it will be comfortable if you have free day at Kathmandu for 1 or 2 days which helps you to make your flight in case of cancellation on the day.
Travel insurance is highly recommended. In case o urgent need, we shall organize a helicopter at our clients request when they have less days to stay in Kathmandu on their return. However, the cost for the helicopter should be borne by the client, which can be claimed through insurance company,