Big Island Hawaii weather 10 day forecast with conditions, climate for Hilo, Kailua Kona, North Shore. Big Island weather today forecast with satellite pictures, news, tsunami warnings.
The Big Island, composed of 5 shield volcanoes, has the most diverse climate in Hawaii, containing 10 of worlds the 15 climate zones. Hilo on the windward side is the wettest city in the U.S., averaging more than 130 inches of rain per year.
Kailua, Kona, and Kohala on the leeward coast, contain the resort areas because they are usually sunny and warm, averaging as little as five inches of rainfall annually. Snow, not usually associated with the tropics, falls at Mauna Kea (Hawaii's highest point at 13,796 feet) and Mauna Loa (location of the U.S.'s only active volcano), Kilauea, in some winter months.
Big Island has a spectacular, diverse climate and enjoys nearly perfect weather. Its daytime temperatures along the coasts generally range from only the mid-70s to the mid-80s most of the year. Big Island is the only state in the U.S. that has never recorded a sub-zero temperature.
Since Big Island has only two seasons-Summer (May through October) and Winter (November through April), you will experience more temperature variation between elevations and windward-leeward coasts, than you will between the seasons. Snow is rare in Hawaii, but occasionally occurs at elevations above 8,000 feet on the Big Island's Mauna Kea and Mauna Loa.
Big Island coastal temperatures can sometimes dip into the 60s during mid-winter and rise into to the 90s in mid-summer. Big Island's heaviest rains occur during winter-month storms, often riding Kona winds, which uncharacteristically blow from the southeast. Flash flooding is not uncommon at such times. Hurricane season in Big Island is June through November. Hurricanes are rare, occurring only about once every 10 years.
Big Island's Beneficial Geography
Located between 19 and 23 degrees north latitude, the inhabited Hawaiian Islands lie only 1,200 to 1,600 miles north of the equator. This fortuitous circumstance of geography means the sun is high in the sky year round, creating temperatures that warm both the land and the surrounding ocean, which varies in temperature from only about 75 degrees to 83 degrees between winter and summer.
Such a warm surrounding ocean keeps the atmosphere above the Hawaiian Islands relatively warm. But two other factors contribute to Big Island's reputation as a tropical paradise with diverse microclimates: Big Island's trade winds, and Big Island's numerous volcanic mountains.
Big Island Volcanic Mountains
The mountains of Big Island, formed millions of years ago though volcanic eruptions from the ocean floor - as the Pacific Plate moves slowly northwest over a hot spots in the earth's mantle - affect Big Island's climate and account for the variations in weather from both island to island and on the same Island.
Big Island Trade Winds
In Big Island, the northeast trade winds, averaging 12 mph, occur about 90% of the time in the summer and about 50% of the time in the winter. They keep humidity at a minimum and ensure moderate temperatures, especially on the windward, unlike other tropical islands closer to the equator.
These cooling winds are created because warm air rises near the equator, flows northward through the upper atmosphere, and cools. Because it becomes heavier as it cools, it falls back to the earth's surface at about 30 degrees latitude, where it flows back toward the equator to replace more rising warm air. This creates cool breezes moving from the northeast to the southwest along the ocean's surface, and over the Hawaiian Islands.