December marks the peak of the wet season in Hawaii.
The weather in Hawaii in December is usually the most humid and rainy, with the average amount of rainfall ranging from 36.4 mm (1.4 in) on Oahu Island to 198 mm (7.8 in) on Kauai Island.
The average maximum temperatures in December range from 22°C (72°F) to 26°C (79°F) across the islands, with the lowest average minimum temperatures being 13°C (55°F) on Kauai Island and 14°C (56°F) on Maui Island.
The seawater temperature remains relatively consistent, with an average temperature of 24.8°C (76.4°F) to 25.2°C (77.4°F).
Keep in mind that the weather can vary greatly depending on the island you are visiting. Read on to find out more details on weather conditions on each Hawaiian island in December.
Average temperature
In the table below, you can find the average high and low temperatures in December on each of the main Hawaiian islands.
In December, the average high temperatures in the Hawaiian islands range from 22°C (72°F) to 26°C (79°F) and average low temperatures range from 13°C (55°F) to 24°C (75°F).
The temperatures in December are slightly cooler than in November, which marks the first month of the wet season in Hawaii.
| Island | Average High | Average Low |
| Hawaii | 25°C / 77°F | 24°C / 75°F |
| Maui | 22°C / 72°F | 14°C / 56°F |
| Oahu (Honolulu) | 26°C / 79°F | 19°C / 66°F |
| Kauai | 22°C / 72°F | 13°C / 55°F |
| Molokai | 25°C / 77°F | 18°C / 64°F |
| Lanai | 24°C / 75°F | 17°C / 62°F |
| Niihau | 25°C / 77°F | 23°C / 73°F |
| Kahoolawe | 25°C / 76°F | 20°C / 68°F |
As a point of reference, the graph below shows the average maximum temperatures in the capital city of Hawaii, Honolulu, for the entire year.
Average seawater temperature
Below is a table with the average seawater temperature on each of the main Hawaiian islands in December.
In December, the average seawater temperature in Hawaii ranges from 24.8°C (76.4°F) to 25.2°C (77.4°F) depending on the island.
The ocean temperature in Hawaii in December is slightly cooler than it is in November, with an average decrease of 0.3°C (0.5°F).
| Island | Average Temperature |
| Hawaii | 25.1°C / 77.2°F |
| Maui | 25.1°C / 77.2°F |
| Oahu (Honolulu) | 25°C / 77°F |
| Kauai | 24.8°C / 76.4°F |
| Molokai | 24.9°C / 76.8°F |
| Lanai | 25.2°C / 77.4°F |
| Niihau | 24.9°C / 76.8°F |
| Kahoolawe | 25.1°C / 77.2°F |
In the chart below, you can find the average seawater temperature in the Honolulu region, across the whole year.
Average rainfall
The table below details the average rainfall and a number of rainy days in December on each of the main Hawaiian islands.
December is a wetter month in Hawaii, with the average amount of rainfall ranging from 41 mm (1.6 in) and 2 rainy days on Hawaii Island to 198 mm (7.8 in) and 16 rainy days on Kauai.
| Island | Total Rainfall | Number of Rainy Days |
| Hawaii | 41 mm / 1.6 in | 2 |
| Maui | 79.7 mm / 3.1 in | 4 |
| Oahu (Honolulu) | 36.4 mm / 1.4 in | 4 |
| Kauai | 198 mm / 7.8 in | 16 |
| Molokai | 49.2 mm / 1.9 in | 2 |
| Lanai | 51.5 mm / 2 in | 4 |
| Niihau | 95 mm / 3.7 in | 4 |
| Kahoolawe | 56.6 mm / 2.2 in | 4 |
To provide more context, the chart below shows the average amount of rainfall by month in Honolulu (Oahu island).
Hawaii weather in December – FAQ
Is December rainy season in Hawaii?
Yes, December is a part of the wet season in Hawaii. The wet season in Hawaii typically lasts from November to March.
Is it warm enough to swim in Hawaii in December?
In December, the ocean temperature in Hawaii is warm enough for swimming.
Depending on the island, the average seawater temperature in December ranges from 24.8°C (76.4°F) to 25.2°C (77.4°F).
The air temperature in Hawaii in December is likewise warm, with average high temperatures ranging from 22°C (72°F) to 26°C (79°F), which makes for a comfortable temperature to swim.
What should I wear in Hawaii in December?
The temperatures in Hawaii in December are warm and pleasant. However December is also a part of the wet season in Hawaii, so you are likely to encounter some rain during your visit.
In terms of clothing, bring a combination of light and breezy items for the warm weather, as well as some layers for the chilly evenings. Also bring a rain jacket or umbrella for when it rains. Don’t forget a swimsuit for swimming and beach sports.
See more guides about Hawaii
