Geography of Hawaii County, Hawaii

Geography of Hawaii County, Hawaii

Hawaii County, encompassing the entirety of the island of Hawaii, often referred to as the “Big Island,” boasts a geography characterized by volcanic landscapes, diverse microclimates, and unique ecosystems. This comprehensive overview will explore the topography, climate, rivers, lakes, and other geographical elements that contribute to the extraordinary character of Hawaii County.


According to existingcountries, Hawaii County is renowned for its remarkable topography shaped by volcanic activity. It is home to five major shield volcanoes: Mauna Kea, Mauna Loa, Hualalai, Kilauea, and Kohala. These volcanoes have played a pivotal role in the formation of the island, creating a diverse range of landscapes.

Mauna Kea and Mauna Loa, the two tallest volcanoes, dominate the island’s central region. Mauna Kea, standing at about 13,796 feet (4,205 meters) above sea level, is known for its snow-capped summit, while Mauna Loa, slightly shorter at 13,678 feet (4,169 meters), is one of the most massive shield volcanoes on Earth. Hualalai, in the west, and Kohala, in the northwest, are both dormant volcanoes, contributing to the island’s varied terrain.

Kilauea, located on the southeastern part of the island, is one of the most active volcanoes globally and has been continuously erupting since 1983. The constant volcanic activity has significantly altered the landscape, creating new land through lava flows that extend to the ocean.


Hawaii County features a range of microclimates due to its diverse topography and the trade winds that sweep across the island. The climate is classified as tropical, with variations in temperature, precipitation, and humidity depending on the specific location.

The coastal areas generally experience warmer temperatures, with daytime highs ranging from the mid-70s to mid-80s°F (24 to 29°C). As elevation increases, temperatures tend to drop, especially on the slopes of Mauna Kea and Mauna Loa, where conditions can be cooler, and occasional snowfall is possible on their summits.

Hawaii County experiences two primary seasons: a dry season, known as “Kau,” typically from April to September, and a wet season, known as “Hooilo,” from October to March. However, microclimates created by the island’s topography mean that some areas receive more rainfall throughout the year, particularly windward slopes, while others remain relatively arid.

Rivers and Lakes:

Hawaii County is not known for extensive river systems or natural lakes due to its volcanic origin and porous terrain. Instead, the island is characterized by intermittent streams, often referred to as “washes” or “gulches,” which can experience significant flows during periods of heavy rainfall. These streams cut through the volcanic landscape, creating canyons and valleys.

While natural lakes are scarce, there are some reservoirs and ponds, often constructed for agricultural purposes and water storage. One notable feature is Lake Waiau, situated near the summit of Mauna Kea. This small alpine lake is one of the highest in the United States, known for its unique ecosystem and cultural significance.

Vegetation and Wildlife:

Hawaii County’s diverse microclimates support a wide array of vegetation, ranging from lush rainforests to arid coastal areas. The island’s original flora and fauna evolved in isolation, leading to the development of many endemic species found nowhere else on Earth.

In the rainforests, native plants such as ohia lehua, hapuu ferns, and koa trees thrive. On the drier leeward slopes, you’ll find a mix of vegetation including kiawe trees, a non-native species introduced to the islands.

The island’s unique wildlife includes a variety of bird species, such as the colorful Hawaii honeycreeper and the endangered Nene goose, the state bird. Marine life is abundant, and the coastal waters are home to spinner dolphins, sea turtles, and various tropical fish.

Conservation efforts in Hawaii County focus on protecting the island’s fragile ecosystems, combating invasive species, and preserving the habitats of endangered species.

Geological Features:

Hawaii County’s geological features are a testament to its volcanic origin. The island is part of the Hawaiian-Emperor seamount chain, a series of underwater mountains formed by the movement of the Pacific tectonic plate over a hotspot. The hotspot, currently located beneath the Big Island, has produced a string of volcanic islands, with the oldest being in the northwest and the youngest in the southeast.

Lava fields, lava tubes, and volcanic craters are prominent geological features on the island. The Thurston Lava Tube, located within Hawaii Volcanoes National Park, provides a glimpse into the underground channels formed by molten lava. The Kilauea Caldera, a massive volcanic crater, is an iconic feature that has undergone significant changes due to ongoing volcanic activity.

Human Impact and Activities:

Hawaii County is home to a diverse and culturally rich population. Hilo, on the eastern side, and Kailua-Kona, on the western side, are the two main population centers. Tourism, agriculture, and astronomy contribute significantly to the local economy.

Tourism is a major industry, with visitors attracted to the island’s natural beauty, volcanic landscapes, and cultural sites. Hawaii Volcanoes National Park, featuring the Kilauea Caldera and other volcanic formations, is a popular destination for tourists interested in geology and natural wonders.

Agriculture is diverse, with crops such as macadamia nuts, coffee, tropical fruits, and flowers being grown in different regions of the island. The fertile volcanic soil contributes to the success of these agricultural endeavors.

The astronomy community also plays a crucial role in Hawaii County. The summit of Mauna Kea hosts some of the world’s most advanced observatories due to its high elevation, clear skies, and low light pollution. The Mauna Kea Observatories contribute to groundbreaking research and observations of the universe.

Cultural and Historical Sites:

Hawaii County has a rich cultural history, with various sites reflecting the island’s indigenous heritage and the influence of different cultures. Puuhonua o Honaunau National Historical Park, also known as the Place of Refuge, preserves ancient Hawaiian structures, temples, and royal grounds.

The Hawaii Volcanoes National Park showcases the island’s geological and cultural history, with petroglyphs, ancient lava tubes, and the sacred Halemaumau Crater.

Historic sites such as the Hulihee Palace in Kailua-Kona and the Lyman House Memorial Museum in Hilo provide insights into the island’s colonial past and the merging of Hawaiian and Western cultures.


Hawaii County, situated on the Big Island, stands as a testament to the forces of nature, with its volcanic landscapes, diverse microclimates, and unique ecosystems. From the towering summits of Mauna Kea and Mauna Loa to the active volcanic flows of Kilauea, the county offers a captivating blend of natural wonders and cultural richness. As Hawaii County continues to balance tourism, agriculture, conservation, and scientific exploration, the commitment to preserving its unique geographical features will be crucial for ensuring a sustainable and resilient future for both the community and the extraordinary environments that define this remarkable part of the Hawaiian archipelago.

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