Shadows retreat when the sun is directly overhead in the islands. Hawaii is the only state to experience the Lahaina noon phenomenon because it is unique to the tropics.
Twice a year, every location in the islands experiences the Lahaina noon. The dates differ slightly and the times vary by minutes along the island chain, from 12:16 on May 18 in Hilo on the Big Island of Hawaii to 12:35 on May 31 in Lihue on Kauai. These photos are from Kailua on Oahu, which experienced Lahaina noon on May 27 at 12:28 pm. They were taken slightly before the exact time because at 12:28 shadows covered the sun as a light mist blew through. When the sun is directly overhead, structures like light poles do not cast a shadow at all. Shadows on other objects are directly beneath them.
The next round of shadow-shrinking will be July 11-24, this time beginning on Kauai and traveling the opposing direction along the islands to the Big Island. I’m not an astronomer, but it has something to do with the sun moving across Hawaii on its way to the Tropic of Cancer for the summer solstice on June 21 and then returning.
According to an article in USA Today newspaper, most of the world has no name for this phenomenon. In Hawaii, the Bishop Museum sponsored a contest around 1990 and the winning name was Lahaina, which means “cruel sun” in Hawaiian. An article last year in the Honolulu Star Bulletin says the ancient Hawaiians had a name for it: kau ka la i ka lolo “the sun rests on the brains.” Nancy Alima All wrote the article and further explained, “It was believed that the moment in which the sun passed over the zenith causing a person’s shadow to disappear was a time of great personal power. At this moment the person’s mana would collect inside, and the person would be aligned with the forces of the universe.” (Noon sun not directly overhead everywhere, May 11, 2010).