Hawaii Weather in September

Although September brings an end to summer, Hawaiian temperatures continue to soar with average daytime temperatures in the mid to high 80s. Your evenings are just as “summery,” staying well within the comfortable 70s range.  

You will find cooler temperatures during the day and night when visiting mountainous areas and volcanoes. The higher you travel, the lower the temperatures, so grab a jacket before you head for the hills.

If you plan to spend a lot of time on the beach, September and October have bragging rights for the warmest ocean temperatures of the year.

Fall means Hawaii will be heading into rainy season soon, but September is still one of the drier months. That means there will be very few rainy days to dampen your spirits. There are a few things to keep in mind when it comes to rain. Drier weather is always a good thing when traveling, but the drier climate of the summer can tend to impact the glorious waterfalls of the area. You can still visit these popular sites, but keep in mind, less rain tends to slow the cascades.

Despite the drier weather, August and September are at the peak of hurricane season in the Pacific. Hawaii has a low risk for hurricanes, but it is still something to think about when booking your vacation.

Hawaii Crowds in September

To estimate crowds for your trip, check local event dates and compare the historical island arrival totals below. September 2027 includes the confirmed Poipu marathon on September 5; check the other organizers' schedules before booking around an event.

Hawaii Costs in September

For September 2027, compare current lodging quotes for your chosen island and travel dates. The Poipu marathon is confirmed for September 5; check official schedules for Kona canoe racing and Oahu festivals before booking around them. Set a fare alert and book when the itinerary and total trip cost work for you.

Hawaii Events & Highlights in September

For September 2027, only the Kauai Marathon date is confirmed among these event calendars as of October 1, 2026. Plan around confirmed dates and check the organizers before booking travel around the others:

• Kauai Marathon and Half Marathon: the organizer confirms Sunday, September 5, 2027, in Poipu. Runners should plan advance packet pickup; visitors staying in Poipu can review the official race information before choosing travel times.
• Aloha Festivals on Oahu: the organizer still lists its 2026 Royal Court opening, Waikiki Hoolaulea, and Floral Parade. Check its 2027 schedule before choosing a Waikiki hotel or travel day around a festival event.
• Queen Liliuokalani Canoe Race: the organizer still lists 2026 dates. Check the 2027 schedule before tying a Kona-side hotel or rental car to race weekend.
• Maui's Festivals of Aloha calendar: the organizer currently lists its 2026 program, with several October events. Confirm the 2027 island and venue schedule before planning travel around a particular performance.

Browse the island event pages below for more ideas, then confirm 2027 dates with the organizers before booking around an event.

For a September 2027 trip, compare lodging quotes by island and check official event schedules before committing to dates. The Kauai Marathon organizer confirms September 5, 2027; use organizer pages for any other event you plan to attend.