The Big Island is a year-round destination with warm coastal temperatures averaging 75-85°F (24-29°C). April-May and September-November offer the best mix of good weather and lower prices, avoiding summer and winter holiday crowds. Note the island's dramatic microclimates: Kona/Kohala (west) stays sunny and dry nearly all year, while Hilo (east) is wet year-round with December-March its rainiest months. Whale watching season (humpback whales) runs December through April.