Things to Do in Kona in September
If you’re planning a trip to the Big Island, you’re probably wondering what things to do in Kona in September actually look like once you land. The short answer: warm water, calmer seas, and some of the best snorkeling conditions you’ll find all year. September sits in a quiet stretch between the busy summer months and the winter holiday crowds, and that makes it a smart time to get out on the water.
At Sea Quest Hawaii, we run small-group snorkeling tours along the South Kona Coast every month of the year, and September is no exception. Below, we’ll walk through what makes this month worth planning around, plus a few land-based activities to fill out your trip.
Why September Is a Great Time to Visit Kona
Kona sits on the leeward side of the Big Island, so it stays dry and sunny most of the year. September keeps that pattern going. Expect warm days, gentle trade winds, and water that’s calm enough for a smooth ride out to the snorkel spots.
Crowds also thin out. Summer break is over, and the winter holiday rush hasn’t started yet. That means easier parking near the harbor, more availability on tour boats, and a slower pace around town.
If you’re trying to decide on the best time to visit Kona, September gives you good weather without the peak-season traffic. It’s one of the reasons so many locals consider it an underrated month for a Big Island trip.
Top Ocean Things to Do in Kona in September
Snorkel With Manta Rays in Kona Any Time of Year
Ask anyone who’s been to Kona what tops their list, and manta ray snorkeling usually comes up first. The good news is that this isn’t a seasonal activity. Manta rays feed in Kona’s waters year round, which means September is just as strong a month for this tour as any other.
What Happens on a Night Manta Ray Snorkel Tour
You’ll head out with our crew after dark and enter the water alongside an experienced guide. Instead of chasing the rays, you hold onto a lit flotation board at the surface. The light draws in plankton, and the plankton draws in the manta rays.
From there, you watch. The rays glide and roll just beneath you, sometimes only inches away. Most guests describe it as one of the most memorable things they’ve done in Hawaii, and it’s easy to see why once you’re floating above one of these animals for the first time.
Why Manta Rays Show Up in Kona Consistently
Manta rays feed on plankton, and Kona’s coastline creates the right conditions for that food source to gather near the surface at night. Because this pattern holds steady through the seasons, you don’t need to time your trip around whale migrations or specific water temperatures to see them. A September night snorkel gives you the same shot at an encounter as a trip booked in January or July.
Best Snorkeling Spots Near Kona in September
Beyond the manta ray tour, South Kona has some of the most talked-about daytime snorkeling on the island. Two spots stand out.
Kealakekua Bay is a marine life conservation district, and for good reason. The water is clear, the reef is healthy, and you’ll likely spot spinner dolphins along with schools of reef fish. It’s also a historically significant site, so our captains share some of that background as you approach by boat.
Honaunau Bay, known locally as Two Step, is another favorite. The entry is easy, the coral is close to the surface, and Hawaiian green sea turtles are a common sight. In September, the water tends to be especially calm, which makes both spots easier to explore for snorkelers of any experience level.
Other Ocean Activities to Pair With Your Kona Snorkel Trip
A snorkel tour doesn’t have to be the only thing you do on the water. The boat ride itself is part of the experience, and September’s calmer seas make it a comfortable one.
Along the way, keep an eye out for spinner dolphins, which are active near the Kona Coast throughout the year. Sea caves and lava tubes also line parts of the coastline, and several of our tours route past them so you can see the terrain up close before getting in the water.
If you want a slower pace, a sunset cruise is worth considering too. Watching the sky change color over the water is a fitting way to close out a day that started with snorkeling.
Things to Do on Land in Kona in September
Not every hour of your trip needs to be spent on a boat. Kona has plenty to offer once you’re back on shore.
Mauna Kea is one of the best stargazing spots in the world, and September’s clear skies make it a strong month for a summit tour. If you’d rather stay closer to sea level, a visit to a local Kona coffee farm gives you a look at how the region’s famous coffee gets grown and processed.
Downtown Kailua-Kona is also worth a walk, especially early in the month. Labor Day weekend brings the Queen Liliuokalani Canoe Race to Kona, drawing paddlers and spectators from across the Pacific. If your trip lines up with it, you’ll get a firsthand look at one of the island’s biggest cultural events.
Enjoy Your September Trip to Kona, Hawaii
Whatever you choose, the things to do in Kona in September list really does start and end with the water. Between the manta rays, the reefs at Kealakekua Bay and Two Step, and the calm September seas, you have a strong case for booking your Kona trip this month. Check availability on our snorkeling tours page and get your dates locked in before Labor Day weekend fills up the calendar.