December in Hawaii represents a significant shift in the islands' weather patterns, marking the official start of the wet season. While the name suggests a frigid month, the reality is a pleasant mix of warm days and increased rainfall, particularly on the windward sides of the islands. This period is characterized by shorter days, longer nights, and a palpable change in atmosphere, as the trade winds shift and bring more frequent showers.
Temperature Ranges Across the Islands
The average temperature in Hawaii in December varies minimally between the major islands, but elevation and location create distinct microclimates. Daytime highs typically range from 78°F (26°C) to 82°F (28°C), offering a comfortable warmth perfect for outdoor activities. Nighttime lows usually fall between 65°F (18°C) and 70°F (21°C), providing a gentle reprieve from the daytime heat and ideal conditions for sleeping.
Regional Variations and Island Specifics
On Oahu, Waikiki experiences an average high of 81°F (27°C), while the windward coast of Kaneohe sees slightly cooler temperatures due to cloud cover. Maui maintains a consistent average temperature in Hawaii in December around 79°F (26°C), with the summit of Haleakala dropping dramatically into the 40s°F (4-9°C). The Big Island’s Kona coast remains one of the warmest and driest spots, often reaching 83°F (28°C), whereas Hilo on the east side deals with more rain and a slightly lower average temperature of 77°F (25°C).
The Shift to the Wet Season
December is the month when Hawaii’s reliable dry season finally gives way to the wet season, fundamentally altering the daily experience. The average rainfall across the islands increases significantly, with some windward locations receiving over 10 inches (250 mm) for the month. This rain is not a constant downpour but often comes in intense, localized bursts, particularly in the afternoons, followed by clear skies.
Sunshine and Ocean Conditions
Despite the rain, December still provides ample sunshine, with an average of 7 to 8 hours of sun per day. The ocean temperature remains inviting, holding steady at a pleasant 75°F (24°C) around the most popular beaches. This combination of warm water and intermittent rain creates the perfect environment for lush vegetation and dramatic waterfalls, which are at their most impressive during this time of year.
Tourism and Practical Considerations
The holiday season makes December the busiest month in Hawaii, with prices for accommodation peaking and flights booking up months in advance. While the rain can disrupt plans, it is rarely severe enough to shut down tourism; instead, it encourages visitors to explore museums, enjoy spa time, or embrace the dramatic stormy scenery. Travelers should pack layers, including a light rain jacket and waterproof shoes, to navigate the transition between sun showers and cooler evenings.
Summary of Key Data
For those planning a trip or simply curious about the climate, the following table summarizes the typical conditions found across the major Hawaiian destinations during December.
