Lāhainā Noon is a tropical solar phenomenon when the Sun culminates at the zenith at solar noon, passing directly overhead (above the subsolar point).[1] The term Lāhainā Noon was coined by the Bishop Museum in Hawaii and is only used locally.

Because the subsolar point travels through the tropics, Hawaii is the only state in the United States to experience Lāhainā Noon.[2] The rest of the states recognize the summer solstice as the event when the sun's rays are closest to being direct.

Hawaii and other locations between the Tropic of Cancer and Tropic of Capricorn receive the sun's direct rays as the apparent path of the sun passes overhead before the summer solstice and retreats equatorward afterwards.

For various locations within the Hawaiian Islands, at the exact times of the Lāhainā Noon which can occur anywhere from 12:16 to 12:43 p.m. Hawaii-Aleutian Standard Time, objects that stand straight up (like flagpoles, telephone poles, etc.) will not cast a shadow. The most southerly points in Hawaii experience Lāhainā Noon on earlier and later dates than the northern parts. For example, in 2001 Hilo on the Island of Hawaiʻi encountered the overhead sun around May 18 and July 24, Kahului, Maui on May 24 and July 18, Honolulu, Oahu on May 26 and July 15 and Lihue, Kauai on May 31 and July 11. Between these two dates, the sun is slightly to the north at noon.[3]

Chosen in a contest sponsored by the Bishop Museum in the 1990s, Lahaina Noon was the selected appellation because lā hainā (the old name for Lāhainā, Hawaii) means "cruel sun" in the Hawaiian language.[4] The ancient Hawaiian name for the event was kau ka lā i ka lolo which literally translates as "the sun rests on the brains."[2][5]

Sourced from Wikipedia.