The Leeds/Bradford to Kathmandu Tribhuvan flight path was viewed by 3,098 users in the past month. Keep an eye out for changes in search interest prior to high and low season.
When travelling, it's generally smart to pack in preparation for rain or any other conditions that may arise. The rainfall in Leeds is roughly greater than that of Kathmandu. You can assume this to be the case over the next 15 days.
Expect the weather to be around 25 °C on average in May. As the temperature peaks, try to get your plans done early, as flight price and availability will have an impact on your travels. The climate in Kathmandu is generally hotter than in Leeds.