Oahu in September

With year-round warm temperatures, beautiful beaches, and aloha spirit, there is never a bad time to visit Oahu, Hawaii.

In September, the summer crowds dwindle and temperatures (slightly) drop, making it one of the best months to visit.

This guide was written by our O’ahu resident!

Is September a Good Time?

Spitting Caves, Oahu, Hawaii

September is a very good time to visit Oahu, Hawaii. You will just miss the summer crowds and overbearing heat. You can go to the beach, hike, shop, attend a local event, visit a museum, or eat amazing Hawaiian cuisine.

Enjoy your trip, but please remember that Oahu is not just a tourist destination but a permanent home to many. When visiting, be sure to “Mālama ka ‘aina,” which means to treat the land with respect.

Weather

Oahu, Hawaii’s weather in September is consistently hot across the island. The average high temperature ranges from 84°F to 86°F (29-31°C). It gets cooler at night, dropping to 78°F (25°C). It also rains less in September compared to the wet winter months.

September in Honolulu | Average High Temperatures:

  • Early September: 87°F (31°C)
    Mid-September: 87°F (31°C)
    Late September: 86°F (30°C)

September in Honolulu | Daily Temperature Progression:

  • Early (7:30 AM): 78°F (25°C)
    Afternoon (1:30 PM): 86°F (30°C)
    Night (11 PM): 78°F (25°C)

Regardless of where you stay on the island, you can expect warm temperatures perfect for swimming.

Rain

Most of Oahu’s hotels and resorts are on its South and Leeward sides, where it is consistently dry and sunny. So if you’re staying at a hotel or resort in September, you can expect clear skies for most of your trip.

Oahu’s Windward side, east of the Ko’olau mountain range, gets more rain. However, if you see rain in the weather forecast, don’t get discouraged. The rain in September is quite scattered, meaning that it will rain for twenty minutes then return to clear, sunny skies.

Wind

Oahu has steady trade winds in the summer months that last well into September. Again, don’t let this fact discourage you. The winds cool you down and make the late-summer humidity bearable. Besides, a windy beach day is better than no beach day!

What to Wear / What to Pack

The style in Oahu, Hawaii is very casual. In September men wear board shorts, an aloha or tee shirt, and slippas (the Hawaiian slang word for flip flops). Women often opt for a sundress and sandals.

When visiting Hawaii, you’ll be spending most of your time outdoors. You should pack items that will help you stay cool and comfortable.

An Oahu packing list might look like this:

  • Reef-safe sunscreen. Residents of Hawaii protect their island and ocean, and they expect visitors to do the same. Do your part by wearing reef-safe sunscreen. It is made of minerals instead of chemicals and will protect the ocean’s sea life.
  • Loose, comfortable clothing. Oahu is hot in September, so it is important to dress accordingly. Cotton and linen are the best materials for hot weather.
  • A light jacket or cardigan. Despite the hot daytime weather, the evenings get cool. A light jacket will come in handy on breezy evenings.
  • Sunhat. If your sunhat doesn’t fold, put it at the bottom of your suitcase and fill it with clothes.
  • Poncho or raincoat. This is a just-in-case item. In a tropical climate, occasional rain is a given.
  • Hiking boots if you plan to go hiking.
  • Swimsuits, board shorts, and UV-protected swim shirts.
  • Empty space (to leave room for souvenirs!)

Crowds

The summer months are busiest in Oahu due to the warm weather and school breaks. Many families vacation during this time. As the school year rolls around, crowds begin to decrease. This makes September a good time to visit.

Best Things to Do in September

Whether staying in downtown Waikiki or the Haleiwa countryside, you can find plenty of things to do in September.

Beaches

September is a great time to visit the beach. You can go snorkeling or go on a sunset beach cruise at Waikiki Beach. On the Windward side, Lanikai Beach is great for swimming and kayaking because of its mild waves.

History

Because of the reduced crowds, September is a great time for a guided history lesson. The Pearl Harbor Museum in Honolulu is a must-do. You can still go on a rainy day because many of the exhibits are indoors or covered.

To immerse yourself in Hawaiian culture, consider checking out the Bishop Museum or the Polynesian Cultural Center.

Hikes

September is also a great time to hike. You can go to Diamond Head in Honolulu or try out the various pillbox hikes scattered across the island. If you can rent a car, the Ma’ili Pillbox Hike in Waianae provides amazing views of Oahu’s Leeward side. It gets hot by mid-day, so it’s best to hike in the early morning.

(I can insert some personal photos of both Diamond Head and Ma’ili if you want).

Events

There are plenty of events to check out in Oahu throughout September. Below are a few suggestions.

Attend Oahu’s annual Waikīkī Ho‘olaule‘a. This is a nighttime street festival held in downtown Honolulu. You can stroll down Kalākaua Avenue and visit booths featuring Hawaiian cuisines, art, and entertainment.

Enjoy some mai tais and attend a traditional Luau at Paradise Cove.

Head to Ko’olina Art Fest any Wednesday of the month to see and purchase art from local artists.

Visit the Bishop Museum After Hours. Take a stroll through Bishop Museum to experience Hawaii’s history and culture, then stay for an evening of entertainment and local cuisines on their great lawn. The theme varies each month.