Lay of the Land
The Big Island is actually made up of five volcanoes. To the north is the long inactive Kohala, whose mountainous slopes are now highly eroded and in some places form great green valleys. Traveling south you'll find Mauna Kea (“white mountain”), a huge volcano and the highest mountain on the island. Next is Hualalai (8,271 feet) whose last eruption in 1801 cut a swath across the Kona Coast. The southern part of the island is dominated by Mauna Loa (“long mountain”), which although about 100 feet shorter than Mauna Kea (13,680 feet) is much more massive. The last eruption of Mauna Loa in 1984 came within only a few miles of the major population center of Hilo. On the flanks of Mauna Loa is the Kilauea (“spewing”) volcano, which has been consistently active during at least the last few centuries.
The chain of Big Island volcanoes effectively divides the island into two sides, the windward and the leeward, with very different climates. As is the case on most of the other islands, the windward sides tend to be much more wet and tropical while the leeward sides are much drier. Indeed, much of the island's east coast is lush and green, while the west coast basks in the sun.
With an average of 129 inches of rain per year, the town of Hilo is perhaps the wettest city in the country. This makes Seattle, with an average of about 36 inches, look like an amateur in comparison. Unlike Seattle, however, the rain in Hilo is usually warm.
The island has been traditionally divided into six regions. Along the dry west coast we find the South and North Kona regions, with the north section being a major tourist destination based in the town of Kailua-Kona. To the far north is the area of Kohala in the region of the old volcano. Its southwest coast is essentially an extension of the Kona coastline until it continues into higher terrain.
The northeast tropical “Hamakua” section of the island has lots of streams, waterfalls, and even some big valleys such as the spectacular Waipi'o. The city of Hilo is found in the south of this region. Another nickname for the Big Island is “the orchid island.” In places, this area indeed does resembles a big garden. Jutting out to the east is the Puna region, where you will find the Hawaii Volcanoes National Park. The very southernmost expanse of the island is the sparsely populated Ka'u district.