December to May is the dry season in Samana. During these months, you can expect sunny, hot and mildly humid conditions. At this time of year, winter squalls move through the northern coast creating rough seas and heavy surges.Air temperatures during the winter months range from 70-80°F (21-26°C) while water temperatures are 75-79°F (24-26°C).On the other hand, December to March is the best time to dive while listening to humpback whales. This is the time of year the island plays host to the humpback whales who migrate from the North Atlantic to the shores of Bavaro and calve in the bay at Samana. As the males are there to impress their females during this season they are incredibly active and often present a spectacular show of splashing and rearing.However, December to May also represents high season for tourism in the Dominican Republic. Therefore, you should book early to get a good deal on accommodation and flights.If you wish to see humpback whales, book your holiday between December and May.