The island of Oahu is home to the state capital of the Hawaiian islands, Honolulu. It's the most populated island in the Hawaiian chain, with about a million inhabitants. Everything is here, in paradise, including kiteboarding and some big air spots to shaka your day away.
Oahu's north shore winter swell sees some giants, and on days that bring gusty-fun winter winds, it can be big air boner aloha heaven. Check out Mokuleia by Dillingham Airfield. You might get lucky and catch some stoke from one of the originals, Top Hat. Stay out of the way of the kitesurf crowd on their foam sticks doing the clockwise rotation and going the wrong way (they go the same direction as the waves...boring!). If you work your way upwind or downwind of the main crowd, you'll have plenty of room to claim a wide block of big air flight path real estate. Once in awhile the surfboard kite crowd tires and returns to the park to talk about bottom turns. That's when you'll have the main waves to your big dick boosting self without getting the stink eye. Visitors and non-kiters will be standing on the shore, in awe and wonder of why you're the only skilled kiteboarder with the ability to wow them and their iPhones. Tons of grassy area to set up. Write your name and contact information on your gear. If and when the winds turn off shore and the kites on the inside fall out of the sky, you'll wish you had one of those surfboards instead of your twin tip boat anchor to swim back to shore. Otherwise, let it all go, kite and all, it'll find it's way to Kuai (50 miles) or the North Atlantic Plastic Trash Gyre, or perhaps the Bearing Sea and The Deadliest Catch show.
On the windward side is Kailua. It has all the options, from flat water near Popoia Island (Flat Island), to big swell and gusty fun next to The Mokes, and smooth wave action near Castles where the wind in the northwest corner of Kailua Bay can be super technical, wind-shadowed, gusty fun! Kailua is probably the most popular (and forgiving) kite spot on Oahu.
The leeward side of the island appears to have delivered the biggest WOO recorded big air at Kahala. The northeast prevailing trade winds get sucked in and the venturi effect through Hawaii Kai that's created by Koko Head and Hanauma Bay works good for some additive thermal+venturi+trade winds=fun!
In late summer, when hurricane season arrives and hurricane watches and warnings get super-duper hyped up by the media, and tourists get prematurely scared off of their vacations, and locals rush to Costco and Target to buy up all the toilet paper and bottled water, check Google Flights for last minute cheap deals and COME HERE TO KITE BIG FUCKING NUCKING WINDS! HURRICANE = FUCKING WIND! I heart hurricanes.