Hilo () is the largest settlement in Hawaii County, Hawaii, United States, which encompasses the Island of Hawaii, and a census-designated place (CDP). The population was 44,186 according to the 2020 census. It is the fourth-largest settlement in the state of Hawaii and largest settlement in the state outside of Oahu.
Hilo is the county seat of the County of Hawaii and is in the District of South Hilo. The city overlooks Hilo Bay and has views of two shield volcanoes, Mauna Loa, an active volcano, and Mauna Kea, a dormant volcano. The Hilo bay-front has been destroyed by tsunamis twice. The majority of human settlement in Hilo stretches from Hilo Bay to Waiākea-Uka, on the flanks of the volcanoes.
Hilo is home to the University of Hawaii at Hilo, ʻImiloa Astronomy Center, as well as the Merrie Monarch Festival, a week-long celebration, including three nights of competition, of ancient and modern hula that takes place annually after Easter. Hilo is also home to the Mauna Loa Macadamia Nut Corporation, one of the world's leading producers of macadamia nuts. Hilo is served by Hilo International Airport.
History
Around 1100 AD, the first Hilo inhabitants arrived, bringing with them Polynesian knowledge and traditions. Although archaeological evidence is scant, oral history has many references to people living in Hilo, along the Wailuku and Wailoa rivers during the time of ancient Hawaii. Oral history gives the meaning of Hilo as "to twist".
Originally, the name "Hilo" applied to a district encompassing much of the east coast of the island of Hawaii, now divided into the District of South Hilo and the District of North Hilo. When William Ellis visited in 1823, the main settlement there was Waiākea on the south shore of Hilo Bay. Missionaries came to the district in the early-to-middle 19th century, founding Haili Church.
Hilo expanded as sugar plantations in the surrounding area created jobs and drew in many workers from Asia. For example, by 1887, 26,000 Chinese workers worked in Hawai'i's sugar cane plantations, one of which was the Hilo Sugar Mill. At that time, the Hilo Sugar Mill produced 3,500 tons of sugar annually.
A breakwater across Hilo Bay was begun in the first decade of the 20th century and completed in 1929. On April 1, 1946, an 8.6-magnitude earthquake near the Aleutian Islands created a tsunami that hit Hilo 4.9 hours later, killing 159 total in the islands, with 96 deaths in Hilo alone. In response, an early warning system, the Pacific Tsunami Warning Center, was established in 1949 to track these killer waves and provide warning. This tsunami also caused the end of the Hawaii Consolidated Railway, and instead the Hawaii Belt Road was built north of Hilo using some of the old railbed.
On May 22, 1960, another tsunami, caused by a 9.5-magnitude earthquake off the coast of Chile that day, claimed 61 lives, allegedly due to the failure of people to heed warning sirens. Low-lying bayfront areas of the city on Waiākea peninsula and along Hilo Bay, previously populated, were rededicated as parks and memorials.
Hilo expanded inland beginning in the 1960s. The downtown found a new role in the 1980s as the city's cultural center with several galleries and museums opening; the Palace Theater reopened in 1998 as an arthouse cinema.
Closure of the sugar plantations (including those in Hāmākua) during the 1990s hurt the local economy, coinciding with a general statewide slump. Hilo in recent years has seen commercial and population growth.
Geography
Hilo is on the eastern and windward side of the island. It is classified by the U.S. Census Bureau as a census-designated place (CDP), and has a total area of , of which is land and of which (8.4%) is water.
Climate
Hilo has a tropical rainforest climate (Köppen: Af), with substantial rainfall throughout the year. Its location on the windward coast (relative to the trade winds), makes it the fourth-wettest city in the United States, behind the southeast Alaskan cities of Whittier, Ketchikan and Yakutat, and one of the wettest in the world. An average of around of rain fell at Hilo International Airport annually between 1981 and 2010, with 272 days of the year receiving some rain. Rainfall in Hilo varies with altitude, with more at higher elevations. At some weather stations in upper Hilo the annual rainfall is above .
Monthly mean temperatures range from in February to in August. The highest recorded temperature was on May 20, 1996, and the lowest on February 21, 1962. The wettest year was 1994 with , and the driest was 1983, with . The most rainfall in one month was in December 1954. The most rainfall in 24 hours was on November 2, 2000.