December in Hawaii typically marks the beginning of the wetter season, particularly on the windward sides of the islands. Average temperatures range from the mid-70s to low 80s Fahrenheit during the day and can dip into the 60s at night. Ocean temperatures remain relatively warm, generally in the upper 70s. Visitors should anticipate occasional rain showers, higher humidity, and increased cloud cover compared to other times of the year. Specific conditions, however, can vary significantly by island and even by location within an island.
Understanding typical Hawaiian weather patterns for this period is beneficial for planning activities and packing appropriately. Travelers seeking sunshine and dry conditions might consider alternative destinations or exploring the leeward (sheltered) sides of the islands. Those interested in whale watching, however, will find December an ideal time as humpback whales begin to arrive in Hawaiian waters. Historically, December has also seen varied weather events, including occasional heavy rainfall and strong winds, highlighting the importance of checking specific forecasts closer to the travel date.