The Big Island offers sunny skies, warm waters, moderate humidity and miles of beautiful beaches. Few people can complain about the climate of the Big Island of Hawaii, which attracts visitors from around the world. While the weather is generally stable and warm throughout the year, local conditions can vary widely from season to season. If you are trying to plan a Big Island vacation, and wondering what it's like during different times of year, we hope you'll find this guide helpful!
Climate on the East Side of the Big Island
The geography of the Big Island plays an important role in regulating the weather. Persistent trade winds from the northeast interact with the island’s large mountains, creating a series of sharply contrasting micro-climates. On the east side of the island, humid onshore winds lead to the development of rain showers on the slopes of Kohala Mountain, Mauna Kea and Mauna Loa. Lush forests, beautiful waterfalls and green pastureland dominate the northeast coast. The wettest location on the island, Waiakea Uka, averages approximately 200 inches of rain per year and is located eight miles southwest of downtown Hilo.
Climate on the West Side of the Big Island - the Kohala Coast
The western side of the island, which includes the Kona-Kohala coast, is dry and sunny most of the year. After traversing the Big Island’s high interior, the trade winds lose most of their moisture and increase in strength as they travel downslope. The driest location in the state of Hawaii is located near Waikoloa Beach Resort and averages just under 10 inches of rain per year. A sharp line delineating the “wet” and “dry” sides of the island can be seen in the town of Waimea, where green pastures border arid shrub-land to the west.
Big Island in the Winter - November to April
The Big Island’s climate is roughly divided into two seasons, winter and summer. During the winter, storm systems in the North Pacific move southward and periodically affect the Big Island. Southerly “kona” winds, which blow the opposite direction of the normal trade winds, bring occasional heavy rain to the entire island between October and March. Also during the winter, large ocean waves originating from storm systems near Alaska affect the island’s north and west facing shorelines. The largest swells of the year, which usually reach 10 - 15ft in height, generally strike between November and February.
During the winter months, from November to April, the Big Island of Hawaiʻi experiences mild and pleasant weather. Coastal regions typically see daytime high temperatures ranging between 78°F and 83°F (25.6°C to 28.3°C), while nighttime lows are approximately 10°F cooler. For instance, Kailua-Kona often has highs around 81°F (27.2°C) and lows near 68°F (20°C) in January. In contrast, higher elevations, such as Waimea and Volcano, encounter cooler conditions, with average temperatures around 60°F (15.5°C) or lower. The windward (eastern) side, including areas like Hilo, tends to receive more rainfall during these months, contributing to its lush landscapes. Conversely, the leeward (western) side, encompassing regions like Kona, remains relatively dry and sunny. Overall, winter on the Big Island offers comfortable temperatures suitable for various outdoor activities, though visitors should be prepared for regional variations in rainfall and temperature.
Big Island in the Summer - May to October
In the summer, the trade winds dominate the local weather pattern. The summers tend to be dryer and slightly warmer, particularly on the island’s west coast. During the months of April - September, powerful storm systems create large ocean waves in the southern hemisphere. As a result, the dominant wave pattern reverses and ocean swells primarily affect the south-facing coasts. Due to the distance between Hawaii and the South Pacific, these summer swells rarely reach the same heights as the winter surf.
Severe weather on the Big Island is rare. In general, the most extreme weather conditions to affect the island are heavy rainstorms during the winter months. Hurricanes, which form during the summer and fall, generally track far south of the island and are not an issue. Cold water east of the state and the Big Island's tall mountains act as barriers to tropical cyclones, so impacts are most often mild or unnoticeable.
During the summer months, the Big Island experiences warm and consistent temperatures, particularly along the coastal regions. Daytime highs typically range from 85°F to 87°F (29.4°C to 30.6°C), with nighttime lows around 74°F to 75°F (23.3°C to 23.9°C). For example, in Kailua-Kona, July sees average high temperatures of approximately 86°F (30°C) and lows near 75°F (24°C). The leeward (western) side, including areas like Kona, remains relatively dry and sunny during these months, while the easter side, such as Hilo, may experience more rainfall, similar to the winter. Overall, summer on the Big Island offers warm temperatures and favorable conditions for outdoor activities, though visitors should be mindful of regional variations in rainfall and humidity.
