About Oahu

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Living On Oahu – Basic Facts And Information About Oahu

Oahu is the third largest and most populated island in the Hawaiian island chain and home to the Hawaii State capitol, the city of Honolulu. Honolulu is the business and financial center of Oahu, as well as home to Hawaii’s major international airport, major seaport, and State University. The entire island of Oahu is Honolulu County in the State of Hawaii.

Population of Oahu

Approximately 953,000, according to 2010 census data.

Population of Honolulu

Around 375,000 (46th most populated city in the United States), according to 2009 data. Also, millions of tourists visit annually.

Size of Oahu

Around 600 square miles (Oahu is smaller than both the Big Island of Hawaii and Maui).

Geology of Oahu

Oahu is the second oldest island of the Hawaiian chain. It was formed by the eruptions of two shield volcanoes, the Waianae and Koolau, after which the respective Mountain Ranges were named, bridged in the middle by the Central Oahu Plain. The highest point of O’ahu, Mt. Ka’ala is 4,003 feet above sea level.

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Oahu’s Climate

Like most of the other Hawaiian islands, Oahu has several micro-climates. In general, the Windward (E/NE) side of the island is windier and rainier than the Honolulu area. The mountain areas are the rainiest areas of the island and the Leeward side of the island is the hottest and driest. And, as you would guess, the areas with the most rain are the most green and tropical. The drier areas are more desert-like, some areas even having cactus! Most of the rain on the island falls in the winter months.

The average temperature on Oahu is between 75-85 degrees F. As a practical matter, there are really only two seasons on this island: Summer (Kau), May-October, and Winter (Holo), November-April. On the hottest days of summer, temperatures may go from a low of about 78 degrees F, to a high of about 92 degrees F. The coldest winter temperatures may go from a low of about 66 degrees F to a high of about 80 degrees F.

Time Zone for O’ahu

Hawaii Standard Time (GMT -10 hours), which is 5 hours behind EST (e.g., New York) and 2 hours behind PST (e.g. San Francisco), but add another hour to each of these during Daylight Savings Time because Hawaii does not observe this change.

Language Spoken on Oahu

American English, though, you will hear many other languages spoken frequently (Hawaiian slang, Japanese, Tongan, Chinese, Korean, Portuguese, etc.)

Cultural Diversity on Oahu

Ethnically Hawaiian (Hawaiian or part-Hawaiian) people make up less than 20% of the population of Oahu, which is a truly a melting pot of Asian and other cultures. Hawaii has seen waves of immigration from many countries and regions including the following:

  • Polynesia - 700 A.D.
  • United States - 1820
  • China - 1852
  • Japan - 1868
  • Portugal - 1878
  • Puerto Rico - 1900
  • Korea - 1903
  • Philippines - 1906

As a result, the Caucasian population of the island is just over 20%, Japanese - around 18%, Filipino - around 14%, Chinese - around 5%, and Tongan/Samoan - around 2% and Black and Korean – each, around 1%. The mixed race population of the island is just around 20%

Oahu’s Currency

US Dollar

Note: Hawaii may seem like a foreign place to some, since it is overseas. But Hawaii is the 50th state of the United States of America, and US citizens here have all the same benefits and protections of US citizenship here, as they do on the mainland. US citizens do not need a passport to travel here.


Oahu’s Major Industries

Travel/tourism, US military/defense, construction, government, manufacturing, agriculture.

Oahu’s Nickname

The “Gathering Place”

Oahu’s Flower


Oahu’s Color

Yellow (mele mele)

Hawaii’s Legal Holidays

New Year’s Day, January 1; Birthday of Martin Luther King, Jr., 3rd Monday in January; Presidents’ Day, 3rd Monday in February; Kuhio Day, March 26; Good Friday, March or April; Memorial Day, last Monday in May; Kamehameha Day, June 11; Independence Day, July 4; Admission Day, 3rd Friday in August; Labor Day, 1st Monday in September; Discoverer’s Day, 2nd Monday in October; Election Day, 1st Tuesday after 1st Monday in November; Veterans Day, November 11; Thanksgiving Day, 4th Thursday in November; Christmas Day, December 25. 

Transportation on Oahu

Air:  Honolulu International Airport (HNL)


  • The Bus – Island-wide public bus system
  • Taxis – many in Honolulu, fewer in other areas
  • Monorail System – in planning phases
  • 4 Major Freeways
    H-1 – Goes across Southern to mid section of island East to West.
    H-2 – Goes from Central Oahu to Northshore
    H-3 - Goes from Central Oahu to Kailua/Kaneohe
    H-201 – Moanalua Fwy - connects Honolulu to Halawa Heights/ Aloha Stadium/ Camp Smith
  • Other Major Highways:
    Pali Highway (61) – Goes from Downtown Honolulu to Kailua, through the Ko’olau Mountain Range
    Likelike Highway (63) – Goes from Honolulu (Kalihi/Chinatown area) to Kaneohe, through the Ko’olau Mountain Range
    Kalanianaole Highway (72) – Goes from East end of H-1 (Kahala area) around S/SE part of O’ahu to Kailua
    Kamehameha Highway - (99 ) Goes through Central Oahu from Hickham/Pearl Harbor through Aiea and Pearl City, heading North and then around the North Shore, through Kaneohe and ending at the Pali Highway, near Kailua. 

Sea: Port of Honolulu

  • Major deepwater port & commerce center
  • Large cruise ships stop and depart here (from Aloha Tower)

Interesting Oahu & Hawaii Facts

  • The Hawaiian islands are one of the most remote places on the earth
  • Persons living in Hawaii have the longest average longevity of the any state in the United States (80 yrs for men/83.2 women) and one of the lowest rates of suicide in the country.
  • ‘lolani Palace is the only royal palace in the United States.
  • Oahu is the site of the famous Pearl Harbor attack by the Japanese in WWII.
  • More than 14,000 coral blocks were taken from offshore reefs to build Kawaiaha’o Church, in Honolulu, in 1836.
  • Honolulu is the 17th most educated city in the U.S., with 34.7 percent of its population holding a bachelor’s degree or higher.
  • The beach in Waikiki is made largely of sand imported from the Big Island of Hawaii.
  • Aloha Tower, today dwarfed by Honolulu high-rises, was the tallest structure on the island when it was built, in 1926.
  • The television show “Hawaii 5-0” is currently filmed here. Also, “Lost” was filmed here on Oahu, mostly on the North Shore. Many other television shows and movies are filmed on Oahu.
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