Lahaina is a place on the island of Maui, Hawaii

Maui is an island in the Central Pacific, part of the Hawaiian archipelago. Sprawling Haleakala National Park encompasses the island’s highest peak, volcanic Haleakala, as well as the pools and waterfalls of Ohe’o Gulch, accessed via scenic, winding Hana Highway. The island’s 30 miles of beaches include golden-crescent Kapalua, sheltered from strong currents by lava-rock promontories.

Great thing about running on Maui is that a) the weather is great; hot or hotter. Never cold.
b) the scene and the flat roads

There is humidity, but, it is not as bad as the islands in the South Pacific south of Hawaii. 

What makes running in Lahaina great is the fact that the road follows the coast and the terrain is as flat as a pancake. Scenic: yes, pretty much the whole run. Watch traffic; since you run on the main road, traffic can be busy on certain parts. Other than the traffic I really enjoyed running here. 

I was able to do two 31-mile (50 km) ultras