The winter season in Hawaii is characterized by rainier weather. In January, some microclimates can experience constant rain for days. Even by mid-April, the end of the rainy season, there is still a daily occurrence of rain showers. However, as April rolls into May, the rains slacken off.
Just like the climate of the islands, the waters around Hawaii stay a constant temperature year-round. However, the winter months bring with them giant swells that crash into the north-facing beaches. The wild surf makes the winter months in Hawaii particularly favored by surfers, although it drives many swimmers into the hotel swimming pools. The calmest time of the year is traditionally in May as winter changes into summer.
The overall temperature in Hawaii never fluctuates more than 10 to 15 degrees. For this reason, many hotels have open-air lobbies. May, however, brings the most consistent temperatures with the fewest fluctuations due to rain or other environmental factors.
Trade winds are the most common winds over the Hawaiian waters, accounting for 70 percent of the wind that blows over Hawaii, according to the Pacific Disaster Center. These winds cool the islands in summer. Trade winds pick up from March through May.
As the wet season ends, there is less protection from the sun's UV rays. Adding to this, the dryer weather motivates visitors to spend more time outdoors. Because of this, sunscreen is an important item to wear if you are going out in Hawaii.