Is there a public shower either at Haleakala National Park or at Kahului Airport on Maui?

it will be pretty cold at haleakala. Best to make your way to sea level. most public beaches have showers. I would go for a swim. I love the salt on my skin. The water is so clean, you just have to rinse afterwards. Have fun

Aloha

There aren't public showers at Haleakala or the Kahului Airport, but there are fresh water showers at all the beaches in Maui. They aren't hot water, but they aren't cold either. The ambient temperature means they are luke warm -- certainly fine for sloshing off after a hike. There is an open shower at the Hawaiian Canoe Club, not far from the airport.

Aloha.

When I went there; I asked the hotel for a late check-out, they asked me to check-out they held my bags and gave me a room to shower....or take a swim with a bar of soap in ocean