December and January is the best time to visit Siem Reap. The weather is dry and cool during these months due to the winter season. It is also the time for various festivals and celebrations, including the Giant Puppet Parade in February. These are the peak months and see a large number of tourists. If you want to skip the crowds, you can plan your visit between June to October, which also gives you the opportunity to witness the glory of ancient temples with the blankets of green hues all around the ruins. Summertime (April & May) is an absolute no-no! Summers are unbearably hot in Cambodia.