The best time to visit Ladakh is during the summer season, which lasts from April through July and with temperatures ranging from 15 to 30 degrees Celsius. Ladakh is famous for its extraordinarily low temperatures practically all year.
Ladakh is a rain shadow region and hence monsoon will not effect your travels. If you're going via flight till Leh, you can proceed during the months of June and July. Traveling by car or a bike to Ladakh can be tricky and you should avoid these months. From May tlll september you can easily navigate around Ladakh without any issue.