Hawaii has relatively mild weather year round giving it the reputation of a tropical paradise. The islands are located in the tropics leading to mostly uniform day lengths and temperatures throughout the year. Hawaii is located in the middle of the ocean thousands of miles away from any larger landmasses. This means that the air that reaches Hawaii has enough time to be moderated by the long journey over the Pacific.

January is considered to be part of winter in Oahu, if you can call it winter. This time of year brings cooler than usual temperatures and extra rain fall than most other times of the year. During the day, the average temperature sits around 80 degrees Fahrenheit (26C), and at night you can expect around 66 degrees Fahrenheit (18C). January is also known to be rainier than usual with an average of 14 rainy days and 2.3 inches of rainfall.

The mountains of Oahu greatly affect the weather that you may encounter while traveling around. You could go from heavy downpours in the North to light mists in the South. In January you can expect to be greeted with mostly mild weather that is far more comfortable than many other destinations in the United States. Depending on your personal preference, the most you will need is some pants and a light jacket, perhaps an umbrella if you want to be fancy.