If you plan any hiking, tennis shoes do not cut it. Bring rugged hiking shoes or boots with good traction and ankle support. This is a rugged place, and good footwear will determine how much you enjoy it. For ocean swimming, you will need water shoes. Even the sandy beaches are full of rocks and the ocean has rocks, coral, etc. that will cut your feet.

As for clothing, cold weather is almost never a concern, with two exceptions. If you plan to go to the summit of Mauna Kea, it can be very cold and requires proper cold-weather gear. And if you visit Hawaiʻi Volcanoes National Park late at night or early in the morning, it can feel cool, especially if there’s wind. Outside of those cases, shorts and light shirts are perfect for the entire trip.

The one item you should plan to carry everywhere is a light rain jacket. Rain can happen anywhere, at any time, and weather here is highly localized. Even on a beautiful day, having a light jacket in your bag is just common sense.

People often ask about “dressing up” to go out. In Hawaiʻi, dressing up usually means closed-toed shoes instead of slippahs and a shirt with a collar. And even then, no one really cares. The entire island is extremely casual, all the time.

Yes, locals really do wear Hawaiian shirts. We call it Aloha wear, and it’s often what people put on when they’re going out to dinner. Feel free to wear them every day, or just stick with a t-shirt. You don’t need long pants. You also don’t need to overpack. We have a washer and dryer available, so you can bring fewer clothes than you normally would.

Finally, plan on buying some Aloha shirts while you’re here. There’s an enormous range of styles and prices, and they make great, genuinely useful keepsakes from the trip.

In short: bring good shoes, dress light, expect rain, and relax. Hawaiʻi is casual, rugged, and best enjoyed when you’re prepared to walk through it.