December in Maui represents a significant shift in the island’s rhythm, as the summer crowds dissipate and a more local atmosphere takes hold. While this is technically the beginning of the Hawaiian winter, the term is relative; temperatures remain consistently mild, hovering between the mid-70s and low 80s Fahrenheit for most coastal areas. This month marks the start of the Kona season, a period characterized by sporadic rain showers on the windward (east) sides of the islands, while the leeward (west) resorts bask in sunshine. For the traveler seeking a balance between comfortable weather and fewer tourists, December offers a unique window into the authentic pulse of Maui.
Understanding Maui’s Microclimates in December
To accurately interpret the average temperature in Maui in December, one must first understand the island’s dramatic microclimates. Unlike a flat landscape, Maui’s topography creates distinct weather zones that can vary by more than 20 degrees Fahrenheit within a short drive. The prevailing northeast trade winds push moisture against the island’s eastern slopes, resulting in lush, tropical conditions in Hana and Haiku. Conversely, the western and southern shores—including the bustling hubs of Lahaina, Kihei, and Wailea—exist in a rain shadow, creating arid environments perfect for sunbathing. When checking the average temperature, location is the single most critical factor.
Temperature Variance Across the Island
On the leeward west side, which houses the majority of the resort developments, the average high temperature in December typically sits around 82°F (28°C). Evening temperatures drop to a comfortable 66°F (19°C), making layered clothing essential for evening activities. In contrast, the windward east side, including Hana and Makawao, experiences slightly cooler averages, with highs around 78°F (26°C) and lows dipping to 62°F (17°C) due to the increased cloud cover and rainfall. Central upcountry regions like Makawao and Kula offer a cooler respite, with temperatures often 10 degrees lower than the coast, averaging highs of 72°F (22°C).
Coastal vs. Upcountry Temperatures
West/South Coast (Kihei, Lahaina, Wailea): Highs of 82°F, lows of 66°F.
Windward East Coast (Hana, Haiku): Highs of 78°F, lows of 62°F.
Upcountry (Makawao, Kula): Highs of 72°F, lows of 59°F.
The Reality of "Winter" Rainfall
December is part of Maui’s wet season, which runs roughly from November through March. However, the rain is rarely a continuous downpour; it manifests as intense, localized showers that often clear within an hour. These "Kona storms" are driven by cold fronts from the north and can dump significant amounts of rain on the windward slopes. For the visitor, this translates to a high likelihood of experiencing a brief shower during a week-long stay, but it rarely ruins an entire day. The rain is often followed by dramatic double rainbows and a refreshing clarity in the air.
Ocean Temperature and Swimming Conditions
Despite the air temperature cooling slightly, the ocean water in December remains inviting. The average ocean temperature around Maui hovers between 74°F (23°C) and 76°F (24°C). While this is cooler than the peak summer months, it is still perfectly suitable for extended swimming, snorkeling, and surfing. Wetsuits are generally not required for recreational activities, although some divers or those sensitive to cooler water might prefer a thin rash guard. The visibility underwater can be exceptional during this time, particularly on the calm, clear days that follow a passing shower.
