The best time to visit Sundarban is during the winter season, which lasts from November to February. During this time, the weather is mild, and the temperature ranges from 15°C to 25°C, making it comfortable for outdoor activities such as boat safaris, nature walks, and birdwatching. The winter season is also the driest time of the year, with minimal rainfall, which makes it easier to explore the Sundarbans without any interruption. The water level in the rivers and canals is also relatively low during this time, which means that the boats can navigate more easily through the mangrove forests. On the other hand, the monsoon season, which lasts from June to September, brings heavy rainfall and strong winds, making it difficult to explore the Sundarbans. The summer season, which lasts from March to May, is hot and humid, and the temperature can soar up to 40°C, making it uncomfortable for outdoor activities. In summary, the best time to visit Sundarban is during the winter season (November to February) when the weather is mild, dry, and comfortable for outdoor activities.