Big Island weather is simply awesome! The Big Island of Hawaii is a tropical island with a fairly mild year-round climate tempered by the Pacific Ocean and northeasterly trade winds. The Big Island boasts 10 of the 15 types of climatic zones in the world. At sea level the average afternoon winter temperature is around 75°F (see below for approximate degrees Celsius) during the coldest months of December and January. August and September are the hottest summer months with temperatures in the low 90s.
Big Island Microclimates – The Big Island’s many different microclimates mean packing for a variety of conditions: swim suits and light hot-weather clothing for the beaches, a lightweight windbreaker for the occasional shower at higher elevations, and more serious protection during inclement conditions when hiking Volcano National Park or Mauna Kea and Mauna Loa.
Big Island Vog – Vog is something you may have heard of and it is important that you are aware of this weather phenomenon as it may affect those with breathing difficulties. Vog (volcanic fog) is a mixture of water vapor, carbon dioxide, and sulfur dioxide. The trade winds blow the vog from its origin at Kilauea Volcano up the coast to Kona. If you have a severe lung condition you may be bothered by the vog, but it is generally not any worse than smog in any major city.
Big Island Dress – Dress is usually quite casual. Sports clothing or beachwear is appropriate for almost all daily activities. Use layers of clothing and be prepared for rain, drizzle and believe it or not, snow, if you plan to do anything at higher elevations like the Big Island Mauna Kea Summit & Stars Adventure.
Big Island Seasons – Winter and Spring (mid-December through mid-April) is the high season when most travelers arrive on the Big Island. This also means that fewer travel bargains are available and that room rates at this time will average 10%-15% higher than the rest of the year.
Big Island Trade Winds – Due to the prevailing trade winds, most rainfall hits the north- or northeast-facing shores, leaving the south and southwest sections relatively dry. As you make your way to various sections of the Big Island, it is interesting to note the differences in terrain brought about by rainfall differentials.
Big Island Landscapes – Besides the trade winds, elevation also plays a role in determining the Big Island weather. You will encounter everything from barren lunar-like desert with cactus bunch grass to lush tropical creepers and wild ginger to a bamboo forest to stands of eucalyptus and pines.
Big Island Temperature Ranges – The following average temperature ranges apply to the Big Island:
- January 65-80°F (18 to 27°C)
- February 65-80°F (18-27°C)
- March 69-81°F (21-27°C)
- April 69-83°F (21-28°C)
- May 70-85°F (21-29°C)
- June 72-86°F (22-30°C)
- July 73-87°F (23-31°C)
- August 74-88°F (23-31°C)
- September 73-88°F (23-31°C)
- October 72-87°F (22-31°C)
- November 69-84°F (21-29°C)
- December 67-81°F (19-27°C)