It's not necessarily "drier" than Oklahoma City or Pierre...it just gets less precipitation. If there was a quiz for average humidity, Honolulu would be much "wetter" that those cities.
For me this was one of my first guesses. It averages about 300 sunny days a year and is extremely dry. It's a beautiful place, but it feels like a desert whenever I'm there (then again, my New Orleans skin feels like that a lot of places lol)
Yes, Kaua'i is often called "the wettest place on earth" with over 450 inches of rain per year. It rained every afternoon when we were there, and I assumed Oahu would have a similar type of weather pattern so I didn't even try it.
I would have been very surprised by this as well, except that I was just visiting Kaneohe, which is about 10 miles from Honolulu and has 37 inches of precipitation. Honolulu is I think one of the best examples of a "rain shadow." The Trade Winds blow from the east, and as the air is lifted up the Koolau Ridge, it dumps rain on the eastern side. Once it crosses the ridge and descends the Honolulu side, there's no more rain. It only rains in Honolulu when the Kona Winds blow, which is rather rare, about 10% of the time.
It's amazing how many microclimates Hawaii has. As a weather enthusiast, I just love it. I think it is one of the most interesting small island chain climates I think. Or maybe I'm just biased as an American, but it's so fun driving around and just seeing the tremendous differences in flora mile to mile even.
Precipitation in Hawaii varies wildly depending on which side of the island you are on. The north shore of Oahu would be very rainy, but Honolulu is on the dry side.
I've read that it is about 317 miles from Lihue, Kauai in the west to Hilo, Hawaii in the east of the Hawaiian islands. Really diverse for only a few hundred miles it seems. Have never been there...yet!
Yep, one of the wettest spots on earth is on Kauai. I should know, I lived there! Think it has to do with the way the mountains and cliffs rise from the ocean. All I remember was it flooding a lot...