07/16/2021
Twice a year, in May and July, the Sun passes directly overhead in Hawaiʻi. On these two days, around local noon, the Sun will be exactly overhead, at a 90o angle, and an upright object such as a flagpole will have no shadow. This phenomenon only occurs in the tropics; the Sun is never directly overhead on any other part of the planet. Hawaiʻi is the only U.S. state in the tropics and thus the only state where this occurs. In 1990 Bishop Museum held a contest to give a name to this phenomenon. The winner was “lāhainā noon.”
The first Lahaina Noons for the year just happened on 5/23 in South Maui and 5/24 in West Maui, but the diminution in shadow lengths will still be noticeable for the next couple of days for a few minutes around 12:23.
The second Lahaina Noons on Maui this year will occur in West Maui on 7/18 at 12:33 and in South Maui on 7/19 at 12:32.
https://gml.noaa.gov/grad/solcalc/